Block-level data replication

ABSTRACT

Certain embodiments described herein relate to an improved block-level replication system. One or more components in an information management system may receive a request to perform a block-level replication between a source storage device and a destination storage device, and depending on the specific replication mode requested, (i) store block-level changes directly to the destination storage device or (ii) first to a recovery point store and then later to the destination storage device.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications, if any, for which a foreign or domesticpriority claim is identified in the Application Data Sheet of thepresent application are hereby incorporated by reference in theirentireties under 37 CFR 1.57.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentand/or the patent disclosure as it appears in the United States Patentand Trademark Office patent file and/or records, but otherwise reservesall copyrights whatsoever.

BACKGROUND

Businesses recognize the commercial value of their data and seekreliable, cost-effective ways to protect the information stored on theircomputer networks while minimizing impact on productivity. A companymight back up critical computing systems such as databases, fileservers, web servers, virtual machines, and so on as part of a daily,weekly, or monthly maintenance schedule. The company may similarlyprotect computing systems used by its employees, such as those used byan accounting department, marketing department, engineering department,and so forth. Given the rapidly expanding volume of data undermanagement, companies also continue to seek innovative techniques formanaging data growth, for example by migrating data to lower-coststorage over time, reducing redundant data, pruning lower priority data,etc. Enterprises also increasingly view their stored data as a valuableasset and look for solutions that leverage their data. For instance,data analysis capabilities, information management, improved datapresentation and access features, and the like, are in increasingdemand.

SUMMARY

Some implementations of data replication may be performed at thefile-system level such that changes to the file system are monitored andreplicated onto a destination device. However, it may be difficult toapply such data replication techniques to systems that do not have afile system. Additionally, if live data is replicated directly onto thedestination device in real time, data errors and abnormalities thatoccur on the source device may also be replicated onto the destinationdevice, rendering the replicated data unusable. Further, the cache usedfor tracking the changes to the source device is typically small, so ifthe source device experiences a high volume of I/O operations or reducednetwork resources, the changes stored in the cache may not be able to bewritten to the destination device fast enough, and the cache may becomefull, causing the data replication to fail. Therefore, an improvedmethod of performing block-level replication is desired.

Certain embodiments described herein relate to an improved informationmanagement system for performing block-level replication. In someembodiments, one or more components in the information management systemcan perform block-level replication with or without using a recoverypoint store configured to store historical replication data depending onthe needs of the user. Additionally, using hydration and dehydrationtechniques, the system can continue performing block-level replicationeven when the system is having storage capacity and/or network issues.Further, dynamically merging recovery points in the recovery point storefor data replication can reduce storage resource consumption. These andother embodiments are described in greater detail below with referenceto the drawings below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIGS. 1F-1H are block diagrams illustrating suitable data structuresthat may be employed by the information management system.

FIG. 2A illustrates a system and technique for synchronizing primarydata to a destination such as a failover site using secondary copy data.

FIG. 2B illustrates an information management system architectureincorporating use of a network file system (NFS) protocol forcommunicating between the primary and secondary storage subsystems.

FIG. 2C is a block diagram of an example of a highly scalable manageddata pool architecture.

FIG. 3 is a block diagram illustrating some portions of a system 300 forperforming block-level data replication according to an embodiment ofthe present disclosure.

FIG. 4 depicts some operations of a method 400 for performingblock-level data replication using a recovery point store according toan embodiment of the present disclosure.

FIG. 5 is a block diagram illustrating a journal entry creation datapath according to an embodiment of the present disclosure.

FIG. 6 depicts a data structure of a recovery point store entryaccording to an embodiment of the present disclosure.

FIG. 7 depicts some operations of a method 700 for performingblock-level data replication in dehydration mode according to anembodiment of the present disclosure.

FIG. 8 depicts some operations of a method 800 for merging recoverypoints in a recovery point store according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION

Detailed descriptions and examples of systems and methods according toone or more embodiments of the present disclosure may be found in thesection entitled Block-Level Data Replication, as well as in the sectionentitled Embodiments, and also in FIGS. 3-8 herein. Furthermore,components and functionality for performing block-level data replicationmay be configured and/or incorporated into information managementsystems such as those described herein in FIGS. 1A-1H and 2A-2C.

Various embodiments described herein are intimately tied to, enabled by,and would not exist except for, computer technology. For example,block-level data replication described herein in reference to variousembodiments cannot reasonably be performed by humans alone, without thecomputer technology upon which they are implemented.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot risk losing critical data. Moreover, runawaydata growth and other modern realities make protecting and managing dataincreasingly difficult. There is therefore a need for efficient,powerful, and user-friendly solutions for protecting and managing dataand for smart and efficient management of data storage. Depending on thesize of the organization, there may be many data production sourceswhich are under the purview of tens, hundreds, or even thousands ofindividuals. In the past, individuals were sometimes responsible formanaging and protecting their own data, and a patchwork of hardware andsoftware point solutions may have been used in any given organization.These solutions were often provided by different vendors and had limitedor no interoperability. Certain embodiments described herein addressthese and other shortcomings of prior approaches by implementingscalable, unified, organization-wide information management, includingdata storage management.

FIG. 1A shows one such information management system 100 (or “system100”), which generally includes combinations of hardware and softwareconfigured to protect and manage data and metadata that are generatedand used by computing devices in system 100. System 100 may be referredto in some embodiments as a “storage management system” or a “datastorage management system.” System 100 performs information managementoperations, some of which may be referred to as “storage operations” or“data storage operations,” to protect and manage the data residing inand/or managed by system 100. The organization that employs system 100may be a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents/publications and patent applications assigned toCommvault Systems, Inc., each of which is hereby incorporated byreference in its entirety herein:

-   -   U.S. Pat. No. 7,035,880, entitled “Modular Backup and Retrieval        System Used in Conjunction With a Storage Area Network”;    -   U.S. Pat. No. 7,107,298, entitled “System And Method For        Archiving Objects In An Information Store”;    -   U.S. Pat. No. 7,246,207, entitled “System and Method for        Dynamically Performing Storage Operations in a Computer        Network”;    -   U.S. Pat. No. 7,315,923, entitled “System And Method For        Combining Data Streams In Pipelined Storage Operations In A        Storage Network”;    -   U.S. Pat. No. 7,343,453, entitled “Hierarchical Systems and        Methods for Providing a Unified View of Storage Information”;    -   U.S. Pat. No. 7,395,282, entitled “Hierarchical Backup and        Retrieval System”;    -   U.S. Pat. No. 7,529,782, entitled “System and Methods for        Performing a Snapshot and for Restoring Data”;    -   U.S. Pat. No. 7,617,262, entitled “System and Methods for        Monitoring Application Data in a Data Replication System”;    -   U.S. Pat. No. 7,734,669, entitled “Managing Copies Of Data”;    -   U.S. Pat. No. 7,747,579, entitled “Metabase for Facilitating        Data Classification”;    -   U.S. Pat. No. 8,156,086, entitled “Systems And Methods For        Stored Data Verification”;    -   U.S. Pat. No. 8,170,995, entitled “Method and System for Offline        Indexing of Content and Classifying Stored Data”;    -   U.S. Pat. No. 8,230,195, entitled “System And Method For        Performing Auxiliary Storage Operations”;    -   U.S. Pat. No. 8,285,681, entitled “Data Object Store and Server        for a Cloud Storage Environment, Including Data Deduplication        and Data Management Across Multiple Cloud Storage Sites”;    -   U.S. Pat. No. 8,307,177, entitled “Systems And Methods For        Management Of Virtualization Data”;    -   U.S. Pat. No. 8,364,652, entitled “Content-Aligned, Block-Based        Deduplication”;    -   U.S. Pat. No. 8,578,120, entitled “Block-Level Single        Instancing”;    -   U.S. Pat. No. 8,954,446, entitled “Client-Side Repository in a        Networked Deduplicated Storage System”;    -   U.S. Pat. No. 9,020,900, entitled “Distributed Deduplicated        Storage System”;    -   U.S. Pat. No. 9,098,495, entitled “Application-Aware and Remote        Single Instance Data Management”;    -   U.S. Pat. No. 9,239,687, entitled “Systems and Methods for        Retaining and Using Data Block Signatures in Data Protection        Operations”;    -   U.S. Patent Application Pub. No. 2006/0224846, entitled “System        and Method to Support Single Instance Storage Operations”;    -   U.S. Patent Application Pub. No. 2014/0201170, entitled “High        Availability Distributed Deduplicated Storage System”;    -   U.S. Patent Application Pub. No. 2016/0350391, entitled        “Replication Using Deduplicated Secondary Copy Data”;    -   U.S. Patent Application Pub. No. 2017/0168903 entitled “Live        Synchronization and Management of Virtual Machines across        Computing and Virtualization Platforms and Using Live        Synchronization to Support Disaster Recovery”;    -   U.S. Patent Application Pub. No. 2017/0193003 entitled        “Redundant and Robust Distributed Deduplication Data Storage        System”;    -   U.S. Patent Application Pub. No. 2017/0235647 entitled “Data        Protection Operations Based on Network Path Information”;    -   U.S. Patent Application Pub. No. 2017/0242871, entitled “Data        Restoration Operations Based on Network Path Information”; and    -   U.S. Patent Application Pub. No. 2017/0185488, entitled        “Application-Level Live Synchronization Across Computing        Platforms Including Synchronizing Co-Resident Applications To        Disparate Standby Destinations And Selectively Synchronizing        Some Applications And Not Others”.

System 100 includes computing devices and computing technologies. Forinstance, system 100 can include one or more client computing devices102 and secondary storage computing devices 106, as well as storagemanager 140 or a host computing device for it. Computing devices caninclude, without limitation, one or more: workstations, personalcomputers, desktop computers, or other types of generally fixedcomputing systems such as mainframe computers, servers, andminicomputers. Other computing devices can include mobile or portablecomputing devices, such as one or more laptops, tablet computers,personal data assistants, mobile phones (such as smartphones), and othermobile or portable computing devices such as embedded computers, set topboxes, vehicle-mounted devices, wearable computers, etc. Servers caninclude mail servers, file servers, database servers, virtual machineservers, and web servers. Any given computing device comprises one ormore processors (e.g., CPU and/or single-core or multi-core processors),as well as corresponding non-transitory computer memory (e.g.,random-access memory (RAM)) for storing computer programs which are tobe executed by the one or more processors. Other computer memory formass storage of data may be packaged/configured with the computingdevice (e.g., an internal hard disk) and/or may be external andaccessible by the computing device (e.g., network-attached storage, astorage array, etc.). In some cases, a computing device includes cloudcomputing resources, which may be implemented as virtual machines. Forinstance, one or more virtual machines may be provided to theorganization by a third-party cloud service vendor.

In some embodiments, computing devices can include one or more virtualmachine(s) running on a physical host computing device (or “hostmachine”) operated by the organization. As one example, the organizationmay use one virtual machine as a database server and another virtualmachine as a mail server, both virtual machines operating on the samehost machine. A Virtual machine (“VM”) is a software implementation of acomputer that does not physically exist and is instead instantiated inan operating system of a physical computer (or host machine) to enableapplications to execute within the VM's environment, i.e., a VM emulatesa physical computer. A VM includes an operating system and associatedvirtual resources, such as computer memory and processor(s). Ahypervisor operates between the VM and the hardware of the physical hostmachine and is generally responsible for creating and running the VMs.Hypervisors are also known in the art as virtual machine monitors or avirtual machine managers or “VMMs”, and may be implemented in software,firmware, and/or specialized hardware installed on the host machine.Examples of hypervisors include ESX Server, by VMware, Inc. of PaloAlto, Calif.; Microsoft Virtual Server and Microsoft Windows ServerHyper-V, both by Microsoft Corporation of Redmond, Wash.; Sun xVM byOracle America Inc. of Santa Clara, Calif.; and Xen by Citrix Systems,Santa Clara, Calif. The hypervisor provides resources to each virtualoperating system such as a virtual processor, virtual memory, a virtualnetwork device, and a virtual disk. Each virtual machine has one or moreassociated virtual disks. The hypervisor typically stores the data ofvirtual disks in files on the file system of the physical host machine,called virtual machine disk files (“VMDK” in VMware lingo) or virtualhard disk image files (in Microsoft lingo). For example, VMware's ESXServer provides the Virtual Machine File System (VMFS) for the storageof virtual machine disk files. A virtual machine reads data from andwrites data to its virtual disk much the way that a physical machinereads data from and writes data to a physical disk. Examples oftechniques for implementing information management in a cloud computingenvironment are described in U.S. Pat. No. 8,285,681. Examples oftechniques for implementing information management in a virtualizedcomputing environment are described in U.S. Pat. No. 8,307,177.

Information management system 100 can also include electronic datastorage devices, generally used for mass storage of data, including,e.g., primary storage devices 104 and secondary storage devices 108.Storage devices can generally be of any suitable type including, withoutlimitation, disk drives, storage arrays (e.g., storage-area network(SAN) and/or network-attached storage (NAS) technology), semiconductormemory (e.g., solid state storage devices), network attached storage(NAS) devices, tape libraries, or other magnetic, non-tape storagedevices, optical media storage devices, DNA/RNA-based memory technology,combinations of the same, etc. In some embodiments, storage devices formpart of a distributed file system. In some cases, storage devices areprovided in a cloud storage environment (e.g., a private cloud or oneoperated by a third-party vendor), whether for primary data or secondarycopies or both.

Depending on context, the term “information management system” can referto generally all of the illustrated hardware and software components inFIG. 1C, or the term may refer to only a subset of the illustratedcomponents. For instance, in some cases, system 100 generally refers toa combination of specialized components used to protect, move, manage,manipulate, analyze, and/or process data and metadata generated byclient computing devices 102. However, system 100 in some cases does notinclude the underlying components that generate and/or store primarydata 112, such as the client computing devices 102 themselves, and theprimary storage devices 104. Likewise secondary storage devices 108(e.g., a third-party provided cloud storage environment) may not be partof system 100. As an example, “information management system” or“storage management system” may sometimes refer to one or more of thefollowing components, which will be described in further detail below:storage manager, data agent, and media agent.

One or more client computing devices 102 may be part of system 100, eachclient computing device 102 having an operating system and at least oneapplication 110 and one or more accompanying data agents executingthereon; and associated with one or more primary storage devices 104storing primary data 112. Client computing device(s) 102 and primarystorage devices 104 may generally be referred to in some cases asprimary storage subsystem 117.

Client Computing Devices, Clients, and Subclients

Typically, a variety of sources in an organization produce data to beprotected and managed. As just one example, in a corporate environmentsuch data sources can be employee workstations and company servers suchas a mail server, a web server, a database server, a transaction server,or the like. In system 100, data generation sources include one or moreclient computing devices 102. A computing device that has a data agent142 installed and operating on it is generally referred to as a “clientcomputing device” 102, and may include any type of computing device,without limitation. A client computing device 102 may be associated withone or more users and/or user accounts.

A “client” is a logical component of information management system 100,which may represent a logical grouping of one or more data agentsinstalled on a client computing device 102. Storage manager 140recognizes a client as a component of system 100, and in someembodiments, may automatically create a client component the first timea data agent 142 is installed on a client computing device 102. Becausedata generated by executable component(s) 110 is tracked by theassociated data agent 142 so that it may be properly protected in system100, a client may be said to generate data and to store the generateddata to primary storage, such as primary storage device 104. However,the terms “client” and “client computing device” as used herein do notimply that a client computing device 102 is necessarily configured inthe client/server sense relative to another computing device such as amail server, or that a client computing device 102 cannot be a server inits own right. As just a few examples, a client computing device 102 canbe and/or include mail servers, file servers, database servers, virtualmachine servers, and/or web servers.

Each client computing device 102 may have application(s) 110 executingthereon which generate and manipulate the data that is to be protectedfrom loss and managed in system 100. Applications 110 generallyfacilitate the operations of an organization, and can include, withoutlimitation, mail server applications (e.g., Microsoft Exchange Server),file system applications, mail client applications (e.g., MicrosoftExchange Client), database applications or database management systems(e.g., SQL, Oracle, SAP, Lotus Notes Database), word processingapplications (e.g., Microsoft Word), spreadsheet applications, financialapplications, presentation applications, graphics and/or videoapplications, browser applications, mobile applications, entertainmentapplications, and so on. Each application 110 may be accompanied by anapplication-specific data agent 142, though not all data agents 142 areapplication-specific or associated with only application. A file system,e.g., Microsoft Windows Explorer, may be considered an application 110and may be accompanied by its own data agent 142. Client computingdevices 102 can have at least one operating system (e.g., MicrosoftWindows, Mac OS X, iOS, IBM z/OS, Linux, other Unix-based operatingsystems, etc.) installed thereon, which may support or host one or morefile systems and other applications 110. In some embodiments, a virtualmachine that executes on a host client computing device 102 may beconsidered an application 110 and may be accompanied by a specific dataagent 142 (e.g., virtual server data agent).

Client computing devices 102 and other components in system 100 can beconnected to one another via one or more electronic communicationpathways 114. For example, a first communication pathway 114 maycommunicatively couple client computing device 102 and secondary storagecomputing device 106; a second communication pathway 114 maycommunicatively couple storage manager 140 and client computing device102; and a third communication pathway 114 may communicatively couplestorage manager 140 and secondary storage computing device 106, etc.(see, e.g., FIG. 1A and FIG. 1C). A communication pathway 114 caninclude one or more networks or other connection types including one ormore of the following, without limitation: the Internet, a wide areanetwork (WAN), a local area network (LAN), a Storage Area Network (SAN),a Fibre Channel (FC) connection, a Small Computer System Interface(SCSI) connection, a virtual private network (VPN), a token ring orTCP/IP based network, an intranet network, a point-to-point link, acellular network, a wireless data transmission system, a two-way cablesystem, an interactive kiosk network, a satellite network, a broadbandnetwork, a baseband network, a neural network, a mesh network, an ad hocnetwork, other appropriate computer or telecommunications networks,combinations of the same or the like. Communication pathways 114 in somecases may also include application programming interfaces (APIs)including, e.g., cloud service provider APIs, virtual machine managementAPIs, and hosted service provider APIs. The underlying infrastructure ofcommunication pathways 114 may be wired and/or wireless, analog and/ordigital, or any combination thereof; and the facilities used may beprivate, public, third-party provided, or any combination thereof,without limitation.

A “subclient” is a logical grouping of all or part of a client's primarydata 112. In general, a subclient may be defined according to how thesubclient data is to be protected as a unit in system 100. For example,a subclient may be associated with a certain storage policy. A givenclient may thus comprise several subclients, each subclient associatedwith a different storage policy. For example, some files may form afirst subclient that requires compression and deduplication and isassociated with a first storage policy. Other files of the client mayform a second subclient that requires a different retention schedule aswell as encryption, and may be associated with a different, secondstorage policy. As a result, though the primary data may be generated bythe same application 110 and may belong to one given client, portions ofthe data may be assigned to different subclients for distinct treatmentby system 100. More detail on subclients is given in regard to storagepolicies below.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 is generally production data or “live” data generatedby the operating system and/or applications 110 executing on clientcomputing device 102. Primary data 112 is generally stored on primarystorage device(s) 104 and is organized via a file system operating onthe client computing device 102. Thus, client computing device(s) 102and corresponding applications 110 may create, access, modify, write,delete, and otherwise use primary data 112. Primary data 112 isgenerally in the native format of the source application 110. Primarydata 112 is an initial or first stored body of data generated by thesource application 110. Primary data 112 in some cases is createdsubstantially directly from data generated by the corresponding sourceapplication 110. It can be useful in performing certain tasks toorganize primary data 112 into units of different granularities. Ingeneral, primary data 112 can include files, directories, file systemvolumes, data blocks, extents, or any other hierarchies or organizationsof data objects. As used herein, a “data object” can refer to (i) anyfile that is currently addressable by a file system or that waspreviously addressable by the file system (e.g., an archive file),and/or to (ii) a subset of such a file (e.g., a data block, an extent,etc.). Primary data 112 may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. See, e.g., FIG. 1B.

It can also be useful in performing certain functions of system 100 toaccess and modify metadata within primary data 112. Metadata generallyincludes information about data objects and/or characteristicsassociated with the data objects. For simplicity herein, it is to beunderstood that, unless expressly stated otherwise, any reference toprimary data 112 generally also includes its associated metadata, butreferences to metadata generally do not include the primary data.Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),user-supplied tags, to/from information for email (e.g., an emailsender, recipient, etc.), creation date, file type (e.g., format orapplication type), last accessed time, application type (e.g., type ofapplication that generated the data object), location/network (e.g., acurrent, past or future location of the data object and network pathwaysto/from the data object), geographic location (e.g., GPS coordinates),frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists(ACLs), system metadata (e.g., registry information), combinations ofthe same or other similar information related to the data object. Inaddition to metadata generated by or related to file systems andoperating systems, some applications 110 and/or other components ofsystem 100 maintain indices of metadata for data objects, e.g., metadataassociated with individual email messages. The use of metadata toperform classification and other functions is described in greaterdetail below.

Primary storage devices 104 storing primary data 112 may be relativelyfast and/or expensive technology (e.g., flash storage, a disk drive, ahard-disk storage array, solid state memory, etc.), typically to supporthigh-performance live production environments. Primary data 112 may behighly changeable and/or may be intended for relatively short termretention (e.g., hours, days, or weeks). According to some embodiments,client computing device 102 can access primary data 112 stored inprimary storage device 104 by making conventional file system calls viathe operating system. Each client computing device 102 is generallyassociated with and/or in communication with one or more primary storagedevices 104 storing corresponding primary data 112. A client computingdevice 102 is said to be associated with or in communication with aparticular primary storage device 104 if it is capable of one or moreof: routing and/or storing data (e.g., primary data 112) to the primarystorage device 104, coordinating the routing and/or storing of data tothe primary storage device 104, retrieving data from the primary storagedevice 104, coordinating the retrieval of data from the primary storagedevice 104, and modifying and/or deleting data in the primary storagedevice 104. Thus, a client computing device 102 may be said to accessdata stored in an associated storage device 104.

Primary storage device 104 may be dedicated or shared. In some cases,each primary storage device 104 is dedicated to an associated clientcomputing device 102, e.g., a local disk drive. In other cases, one ormore primary storage devices 104 can be shared by multiple clientcomputing devices 102, e.g., via a local network, in a cloud storageimplementation, etc. As one example, primary storage device 104 can be astorage array shared by a group of client computing devices 102, such asEMC Clariion, EMC Symmetrix, EMC Celerra, Dell EqualLogic, IBM XIV,NetApp FAS, HP EVA, and HP 3PAR.

System 100 may also include hosted services (not shown), which may behosted in some cases by an entity other than the organization thatemploys the other components of system 100. For instance, the hostedservices may be provided by online service providers. Such serviceproviders can provide social networking services, hosted email services,or hosted productivity applications or other hosted applications such assoftware-as-a-service (SaaS), platform-as-a-service (PaaS), applicationservice providers (ASPs), cloud services, or other mechanisms fordelivering functionality via a network. As it services users, eachhosted service may generate additional data and metadata, which may bemanaged by system 100, e.g., as primary data 112. In some cases, thehosted services may be accessed using one of the applications 110. As anexample, a hosted mail service may be accessed via browser running on aclient computing device 102.

Secondary Copies and Exemplary Secondary Storage Devices

Primary data 112 stored on primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112. Or primary storagedevices 104 can be damaged, lost, or otherwise corrupted. For recoveryand/or regulatory compliance purposes, it is therefore useful togenerate and maintain copies of primary data 112. Accordingly, system100 includes one or more secondary storage computing devices 106 and oneor more secondary storage devices 108 configured to create and store oneor more secondary copies 116 of primary data 112 including itsassociated metadata. The secondary storage computing devices 106 and thesecondary storage devices 108 may be referred to as secondary storagesubsystem 118.

Secondary copies 116 can help in search and analysis efforts and meetother information management goals as well, such as: restoring dataand/or metadata if an original version is lost (e.g., by deletion,corruption, or disaster); allowing point-in-time recovery; complyingwith regulatory data retention and electronic discovery (e-discovery)requirements; reducing utilized storage capacity in the productionsystem and/or in secondary storage; facilitating organization and searchof data; improving user access to data files across multiple computingdevices and/or hosted services; and implementing data retention andpruning policies.

A secondary copy 116 can comprise a separate stored copy of data that isderived from one or more earlier-created stored copies (e.g., derivedfrom primary data 112 or from another secondary copy 116). Secondarycopies 116 can include point-in-time data, and may be intended forrelatively long-term retention before some or all of the data is movedto other storage or discarded. In some cases, a secondary copy 116 maybe in a different storage device than other previously stored copies;and/or may be remote from other previously stored copies. Secondarycopies 116 can be stored in the same storage device as primary data 112.For example, a disk array capable of performing hardware snapshotsstores primary data 112 and creates and stores hardware snapshots of theprimary data 112 as secondary copies 116. Secondary copies 116 may bestored in relatively slow and/or lower cost storage (e.g., magnetictape). A secondary copy 116 may be stored in a backup or archive format,or in some other format different from the native source applicationformat or other format of primary data 112.

Secondary storage computing devices 106 may index secondary copies 116(e.g., using a media agent 144), enabling users to browse and restore ata later time and further enabling the lifecycle management of theindexed data. After creation of a secondary copy 116 that representscertain primary data 112, a pointer or other location indicia (e.g., astub) may be placed in primary data 112, or be otherwise associated withprimary data 112, to indicate the current location of a particularsecondary copy 116. Since an instance of a data object or metadata inprimary data 112 may change over time as it is modified by application110 (or hosted service or the operating system), system 100 may createand manage multiple secondary copies 116 of a particular data object ormetadata, each copy representing the state of the data object in primarydata 112 at a particular point in time. Moreover, since an instance of adata object in primary data 112 may eventually be deleted from primarystorage device 104 and the file system, system 100 may continue tomanage point-in-time representations of that data object, even thoughthe instance in primary data 112 no longer exists. For virtual machines,the operating system and other applications 110 of client computingdevice(s) 102 may execute within or under the management ofvirtualization software (e.g., a VMM), and the primary storage device(s)104 may comprise a virtual disk created on a physical storage device.System 100 may create secondary copies 116 of the files or other dataobjects in a virtual disk file and/or secondary copies 116 of the entirevirtual disk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 are distinguishable from corresponding primary data112. First, secondary copies 116 can be stored in a different formatfrom primary data 112 (e.g., backup, archive, or other non-nativeformat). For this or other reasons, secondary copies 116 may not bedirectly usable by applications 110 or client computing device 102(e.g., via standard system calls or otherwise) without modification,processing, or other intervention by system 100 which may be referred toas “restore” operations. Secondary copies 116 may have been processed bydata agent 142 and/or media agent 144 in the course of being created(e.g., compression, deduplication, encryption, integrity markers,indexing, formatting, application-aware metadata, etc.), and thussecondary copy 116 may represent source primary data 112 withoutnecessarily being exactly identical to the source.

Second, secondary copies 116 may be stored on a secondary storage device108 that is inaccessible to application 110 running on client computingdevice 102 and/or hosted service. Some secondary copies 116 may be“offline copies,” in that they are not readily available (e.g., notmounted to tape or disk). Offline copies can include copies of data thatsystem 100 can access without human intervention (e.g., tapes within anautomated tape library, but not yet mounted in a drive), and copies thatthe system 100 can access only with some human intervention (e.g., tapeslocated at an offsite storage site).

Using Intermediate Devices for Creating Secondary Copies—SecondaryStorage Computing Devices

Creating secondary copies can be challenging when hundreds or thousandsof client computing devices 102 continually generate large volumes ofprimary data 112 to be protected. Also, there can be significantoverhead involved in the creation of secondary copies 116. Moreover,specialized programmed intelligence and/or hardware capability isgenerally needed for accessing and interacting with secondary storagedevices 108. Client computing devices 102 may interact directly with asecondary storage device 108 to create secondary copies 116, but in viewof the factors described above, this approach can negatively impact theability of client computing device 102 to serve/service application 110and produce primary data 112. Further, any given client computing device102 may not be optimized for interaction with certain secondary storagedevices 108.

Thus, system 100 may include one or more software and/or hardwarecomponents which generally act as intermediaries between clientcomputing devices 102 (that generate primary data 112) and secondarystorage devices 108 (that store secondary copies 116). In addition tooff-loading certain responsibilities from client computing devices 102,these intermediate components provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability and improve system performance. For instance, usingspecialized secondary storage computing devices 106 and media agents 144for interfacing with secondary storage devices 108 and/or for performingcertain data processing operations can greatly improve the speed withwhich system 100 performs information management operations and can alsoimprove the capacity of the system to handle large numbers of suchoperations, while reducing the computational load on the productionenvironment of client computing devices 102. The intermediate componentscan include one or more secondary storage computing devices 106 as shownin FIG. 1A and/or one or more media agents 144. Media agents arediscussed further below (e.g., with respect to FIGS. 1C-1E). Thesespecial-purpose components of system 100 comprise specialized programmedintelligence and/or hardware capability for writing to, reading from,instructing, communicating with, or otherwise interacting with secondarystorage devices 108.

Secondary storage computing device(s) 106 can comprise any of thecomputing devices described above, without limitation. In some cases,secondary storage computing device(s) 106 also include specializedhardware componentry and/or software intelligence (e.g., specializedinterfaces) for interacting with certain secondary storage device(s) 108with which they may be specially associated.

To create a secondary copy 116 involving the copying of data fromprimary storage subsystem 117 to secondary storage subsystem 118, clientcomputing device 102 may communicate the primary data 112 to be copied(or a processed version thereof generated by a data agent 142) to thedesignated secondary storage computing device 106, via a communicationpathway 114. Secondary storage computing device 106 in turn may furtherprocess and convey the data or a processed version thereof to secondarystorage device 108. One or more secondary copies 116 may be created fromexisting secondary copies 116, such as in the case of an auxiliary copyoperation, described further below.

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view of some specific examples of primary datastored on primary storage device(s) 104 and secondary copy data storedon secondary storage device(s) 108, with other components of the systemremoved for the purposes of illustration. Stored on primary storagedevice(s) 104 are primary data 112 objects including word processingdocuments 119A-B, spreadsheets 120, presentation documents 122, videofiles 124, image files 126, email mailboxes 128 (and corresponding emailmessages 129A-C), HTML/XML or other types of markup language files 130,databases 132 and corresponding tables or other data structures133A-133C. Some or all primary data 112 objects are associated withcorresponding metadata (e.g., “Meta1-11”), which may include file systemmetadata and/or application-specific metadata. Stored on the secondarystorage device(s) 108 are secondary copy 116 data objects 134A-C whichmay include copies of or may otherwise represent corresponding primarydata 112.

Secondary copy data objects 134A-C can individually represent more thanone primary data object. For example, secondary copy data object 134Arepresents three separate primary data objects 133C, 122, and 129C(represented as 133C′, 122′, and 129C′, respectively, and accompanied bycorresponding metadata Meta11, Meta3, and Meta8, respectively).Moreover, as indicated by the prime mark (′), secondary storagecomputing devices 106 or other components in secondary storage subsystem118 may process the data received from primary storage subsystem 117 andstore a secondary copy including a transformed and/or supplementedrepresentation of a primary data object and/or metadata that isdifferent from the original format, e.g., in a compressed, encrypted,deduplicated, or other modified format. For instance, secondary storagecomputing devices 106 can generate new metadata or other informationbased on said processing, and store the newly generated informationalong with the secondary copies. Secondary copy data object 1346represents primary data objects 120, 133B, and 119A as 120′, 133B′, and119A′, respectively, accompanied by corresponding metadata Meta2,Meta10, and Meta1, respectively. Also, secondary copy data object 134Crepresents primary data objects 133A, 119B, and 129A as 133A′, 119B′,and 129A′, respectively, accompanied by corresponding metadata Meta9,Meta5, and Meta6, respectively.

Exemplary Information Management System Architecture

System 100 can incorporate a variety of different hardware and softwarecomponents, which can in turn be organized with respect to one anotherin many different configurations, depending on the embodiment. There arecritical design choices involved in specifying the functionalresponsibilities of the components and the role of each component insystem 100. Such design choices can impact how system 100 performs andadapts to data growth and other changing circumstances. FIG. 1C shows asystem 100 designed according to these considerations and includes:storage manager 140, one or more data agents 142 executing on clientcomputing device(s) 102 and configured to process primary data 112, andone or more media agents 144 executing on one or more secondary storagecomputing devices 106 for performing tasks involving secondary storagedevices 108.

Storage Manager

Storage manager 140 is a centralized storage and/or information managerthat is configured to perform certain control functions and also tostore certain critical information about system 100—hence storagemanager 140 is said to manage system 100. As noted, the number ofcomponents in system 100 and the amount of data under management can belarge. Managing the components and data is therefore a significant task,which can grow unpredictably as the number of components and data scaleto meet the needs of the organization. For these and other reasons,according to certain embodiments, responsibility for controlling system100, or at least a significant portion of that responsibility, isallocated to storage manager 140. Storage manager 140 can be adaptedindependently according to changing circumstances, without having toreplace or re-design the remainder of the system. Moreover, a computingdevice for hosting and/or operating as storage manager 140 can beselected to best suit the functions and networking needs of storagemanager 140. These and other advantages are described in further detailbelow and with respect to FIG. 1D.

Storage manager 140 may be a software module or other application hostedby a suitable computing device. In some embodiments, storage manager 140is itself a computing device that performs the functions describedherein. Storage manager 140 comprises or operates in conjunction withone or more associated data structures such as a dedicated database(e.g., management database 146), depending on the configuration. Thestorage manager 140 generally initiates, performs, coordinates, and/orcontrols storage and other information management operations performedby system 100, e.g., to protect and control primary data 112 andsecondary copies 116. In general, storage manager 140 is said to managesystem 100, which includes communicating with, instructing, andcontrolling in some circumstances components such as data agents 142 andmedia agents 144, etc.

As shown by the dashed arrowed lines 114 in FIG. 1C, storage manager 140may communicate with, instruct, and/or control some or all elements ofsystem 100, such as data agents 142 and media agents 144. In thismanner, storage manager 140 manages the operation of various hardwareand software components in system 100. In certain embodiments, controlinformation originates from storage manager 140 and status as well asindex reporting is transmitted to storage manager 140 by the managedcomponents, whereas payload data and metadata are generally communicatedbetween data agents 142 and media agents 144 (or otherwise betweenclient computing device(s) 102 and secondary storage computing device(s)106), e.g., at the direction of and under the management of storagemanager 140. Control information can generally include parameters andinstructions for carrying out information management operations, suchas, without limitation, instructions to perform a task associated withan operation, timing information specifying when to initiate a task,data path information specifying what components to communicate with oraccess in carrying out an operation, and the like. In other embodiments,some information management operations are controlled or initiated byother components of system 100 (e.g., by media agents 144 or data agents142), instead of or in combination with storage manager 140.

According to certain embodiments, storage manager 140 provides one ormore of the following functions:

-   -   communicating with data agents 142 and media agents 144,        including transmitting instructions, messages, and/or queries,        as well as receiving status reports, index information,        messages, and/or queries, and responding to same;    -   initiating execution of information management operations;    -   initiating restore and recovery operations;    -   managing secondary storage devices 108 and inventory/capacity of        the same;    -   allocating secondary storage devices 108 for secondary copy        operations;    -   reporting, searching, and/or classification of data in system        100;    -   monitoring completion of and status reporting related to        information management operations and jobs;    -   tracking movement of data within system 100;    -   tracking age information relating to secondary copies 116,        secondary storage devices 108, comparing the age information        against retention guidelines, and initiating data pruning when        appropriate;    -   tracking logical associations between components in system 100;    -   protecting metadata associated with system 100, e.g., in        management database 146;    -   implementing job management, schedule management, event        management, alert management, reporting, job history        maintenance, user security management, disaster recovery        management, and/or user interfacing for system administrators        and/or end users of system 100;    -   sending, searching, and/or viewing of log files; and    -   implementing operations management functionality.

Storage manager 140 may maintain an associated database 146 (or “storagemanager database 146” or “management database 146”) ofmanagement-related data and information management policies 148.Database 146 is stored in computer memory accessible by storage manager140. Database 146 may include a management index 150 (or “index 150”) orother data structure(s) that may store: logical associations betweencomponents of the system; user preferences and/or profiles (e.g.,preferences regarding encryption, compression, or deduplication ofprimary data or secondary copies; preferences regarding the scheduling,type, or other aspects of secondary copy or other operations; mappingsof particular information management users or user accounts to certaincomputing devices or other components, etc.; management tasks; mediacontainerization; other useful data; and/or any combination thereof. Forexample, storage manager 140 may use index 150 to track logicalassociations between media agents 144 and secondary storage devices 108and/or movement of data to/from secondary storage devices 108. Forinstance, index 150 may store data associating a client computing device102 with a particular media agent 144 and/or secondary storage device108, as specified in an information management policy 148.

Administrators and others may configure and initiate certain informationmanagement operations on an individual basis. But while this may beacceptable for some recovery operations or other infrequent tasks, it isoften not workable for implementing on-going organization-wide dataprotection and management. Thus, system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations on an automated basis. Generally, an informationmanagement policy 148 can include a stored data structure or otherinformation source that specifies parameters (e.g., criteria and rules)associated with storage management or other information managementoperations. Storage manager 140 can process an information managementpolicy 148 and/or index 150 and, based on the results, identify aninformation management operation to perform, identify the appropriatecomponents in system 100 to be involved in the operation (e.g., clientcomputing devices 102 and corresponding data agents 142, secondarystorage computing devices 106 and corresponding media agents 144, etc.),establish connections to those components and/or between thosecomponents, and/or instruct and control those components to carry outthe operation. In this manner, system 100 can translate storedinformation into coordinated activity among the various computingdevices in system 100.

Management database 146 may maintain information management policies 148and associated data, although information management policies 148 can bestored in computer memory at any appropriate location outside managementdatabase 146. For instance, an information management policy 148 such asa storage policy may be stored as metadata in a media agent database 152or in a secondary storage device 108 (e.g., as an archive copy) for usein restore or other information management operations, depending on theembodiment. Information management policies 148 are described furtherbelow. According to certain embodiments, management database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding subclientdata were protected and where the secondary copies are stored and whichmedia agent 144 performed the storage operation(s)). This and othermetadata may additionally be stored in other locations, such as atsecondary storage computing device 106 or on the secondary storagedevice 108, allowing data recovery without the use of storage manager140 in some cases. Thus, management database 146 may comprise dataneeded to kick off secondary copy operations (e.g., storage policies,schedule policies, etc.), status and reporting information aboutcompleted jobs (e.g., status and error reports on yesterday's backupjobs), and additional information sufficient to enable restore anddisaster recovery operations (e.g., media agent associations, locationindexing, content indexing, etc.).

Storage manager 140 may include a jobs agent 156, a user interface 158,and a management agent 154, all of which may be implemented asinterconnected software modules or application programs. These aredescribed further below.

Jobs agent 156 in some embodiments initiates, controls, and/or monitorsthe status of some or all information management operations previouslyperformed, currently being performed, or scheduled to be performed bysystem 100. A job is a logical grouping of information managementoperations such as daily storage operations scheduled for a certain setof subclients (e.g., generating incremental block-level backup copies116 at a certain time every day for database files in a certaingeographical location). Thus, jobs agent 156 may access informationmanagement policies 148 (e.g., in management database 146) to determinewhen, where, and how to initiate/control jobs in system 100.

Storage Manager User Interfaces

User interface 158 may include information processing and displaysoftware, such as a graphical user interface (GUI), an applicationprogram interface (API), and/or other interactive interface(s) throughwhich users and system processes can retrieve information about thestatus of information management operations or issue instructions tostorage manager 140 and other components. Via user interface 158, usersmay issue instructions to the components in system 100 regardingperformance of secondary copy and recovery operations. For example, auser may modify a schedule concerning the number of pending secondarycopy operations. As another example, a user may employ the GUI to viewthe status of pending secondary copy jobs or to monitor the status ofcertain components in system 100 (e.g., the amount of capacity left in astorage device). Storage manager 140 may track information that permitsit to select, designate, or otherwise identify content indices,deduplication databases, or similar databases or resources or data setswithin its information management cell (or another cell) to be searchedin response to certain queries. Such queries may be entered by the userby interacting with user interface 158.

Various embodiments of information management system 100 may beconfigured and/or designed to generate user interface data usable forrendering the various interactive user interfaces described. The userinterface data may be used by system 100 and/or by another system,device, and/or software program (for example, a browser program), torender the interactive user interfaces. The interactive user interfacesmay be displayed on, for example, electronic displays (including, forexample, touch-enabled displays), consoles, etc., whetherdirect-connected to storage manager 140 or communicatively coupledremotely, e.g., via an internet connection. The present disclosuredescribes various embodiments of interactive and dynamic userinterfaces, some of which may be generated by user interface agent 158,and which are the result of significant technological development. Theuser interfaces described herein may provide improved human-computerinteractions, allowing for significant cognitive and ergonomicefficiencies and advantages over previous systems, including reducedmental workloads, improved decision-making, and the like. User interface158 may operate in a single integrated view or console (not shown). Theconsole may support a reporting capability for generating a variety ofreports, which may be tailored to a particular aspect of informationmanagement.

User interfaces are not exclusive to storage manager 140 and in someembodiments a user may access information locally from a computingdevice component of system 100. For example, some information pertainingto installed data agents 142 and associated data streams may beavailable from client computing device 102. Likewise, some informationpertaining to media agents 144 and associated data streams may beavailable from secondary storage computing device 106.

Storage Manager Management Agent

Management agent 154 can provide storage manager 140 with the ability tocommunicate with other components within system 100 and/or with otherinformation management cells via network protocols and applicationprogramming interfaces (APIs) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs, without limitation. Management agent 154 alsoallows multiple information management cells to communicate with oneanother. For example, system 100 in some cases may be one informationmanagement cell in a network of multiple cells adjacent to one anotheror otherwise logically related, e.g., in a WAN or LAN. With thisarrangement, the cells may communicate with one another throughrespective management agents 154. Inter-cell communications andhierarchy is described in greater detail in e.g., U.S. Pat. No.7,343,453.

Information Management Cell

An “information management cell” (or “storage operation cell” or “cell”)may generally include a logical and/or physical grouping of acombination of hardware and software components associated withperforming information management operations on electronic data,typically one storage manager 140 and at least one data agent 142(executing on a client computing device 102) and at least one mediaagent 144 (executing on a secondary storage computing device 106). Forinstance, the components shown in FIG. 1C may together form aninformation management cell. Thus, in some configurations, a system 100may be referred to as an information management cell or a storageoperation cell. A given cell may be identified by the identity of itsstorage manager 140, which is generally responsible for managing thecell.

Multiple cells may be organized hierarchically, so that cells mayinherit properties from hierarchically superior cells or be controlledby other cells in the hierarchy (automatically or otherwise).Alternatively, in some embodiments, cells may inherit or otherwise beassociated with information management policies, preferences,information management operational parameters, or other properties orcharacteristics according to their relative position in a hierarchy ofcells. Cells may also be organized hierarchically according to function,geography, architectural considerations, or other factors useful ordesirable in performing information management operations. For example,a first cell may represent a geographic segment of an enterprise, suchas a Chicago office, and a second cell may represent a differentgeographic segment, such as a New York City office. Other cells mayrepresent departments within a particular office, e.g., human resources,finance, engineering, etc. Where delineated by function, a first cellmay perform one or more first types of information management operations(e.g., one or more first types of secondary copies at a certainfrequency), and a second cell may perform one or more second types ofinformation management operations (e.g., one or more second types ofsecondary copies at a different frequency and under different retentionrules). In general, the hierarchical information is maintained by one ormore storage managers 140 that manage the respective cells (e.g., incorresponding management database(s) 146).

Data Agents

A variety of different applications 110 can operate on a given clientcomputing device 102, including operating systems, file systems,database applications, e-mail applications, and virtual machines, justto name a few. And, as part of the process of creating and restoringsecondary copies 116, the client computing device 102 may be tasked withprocessing and preparing the primary data 112 generated by these variousapplications 110. Moreover, the nature of the processing/preparation candiffer across application types, e.g., due to inherent structural,state, and formatting differences among applications 110 and/or theoperating system of client computing device 102. Each data agent 142 istherefore advantageously configured in some embodiments to assist in theperformance of information management operations based on the type ofdata that is being protected at a client-specific and/orapplication-specific level.

Data agent 142 is a component of information system 100 and is generallydirected by storage manager 140 to participate in creating or restoringsecondary copies 116. Data agent 142 may be a software program (e.g., inthe form of a set of executable binary files) that executes on the sameclient computing device 102 as the associated application 110 that dataagent 142 is configured to protect. Data agent 142 is generallyresponsible for managing, initiating, or otherwise assisting in theperformance of information management operations in reference to itsassociated application(s) 110 and corresponding primary data 112 whichis generated/accessed by the particular application(s) 110. Forinstance, data agent 142 may take part in copying, archiving, migrating,and/or replicating of certain primary data 112 stored in the primarystorage device(s) 104. Data agent 142 may receive control informationfrom storage manager 140, such as commands to transfer copies of dataobjects and/or metadata to one or more media agents 144. Data agent 142also may compress, deduplicate, and encrypt certain primary data 112, aswell as capture application-related metadata before transmitting theprocessed data to media agent 144. Data agent 142 also may receiveinstructions from storage manager 140 to restore (or assist inrestoring) a secondary copy 116 from secondary storage device 108 toprimary storage 104, such that the restored data may be properlyaccessed by application 110 in a suitable format as though it wereprimary data 112.

Each data agent 142 may be specialized for a particular application 110.For instance, different individual data agents 142 may be designed tohandle Microsoft Exchange data, Lotus Notes data, Microsoft Windows filesystem data, Microsoft Active Directory Objects data, SQL Server data,Share Point data, Oracle database data, SAP database data, virtualmachines and/or associated data, and other types of data. A file systemdata agent, for example, may handle data files and/or other file systeminformation. If a client computing device 102 has two or more types ofdata 112, a specialized data agent 142 may be used for each data type.For example, to backup, migrate, and/or restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use: (1)a Microsoft Exchange Mailbox data agent 142 to back up the Exchangemailboxes; (2) a Microsoft Exchange Database data agent 142 to back upthe Exchange databases; (3) a Microsoft Exchange Public Folder dataagent 142 to back up the Exchange Public Folders; and (4) a MicrosoftWindows File System data agent 142 to back up the file system of clientcomputing device 102. In this example, these specialized data agents 142are treated as four separate data agents 142 even though they operate onthe same client computing device 102. Other examples may include archivemanagement data agents such as a migration archiver or a compliancearchiver, Quick Recovery® agents, and continuous data replicationagents. Application-specific data agents 142 can provide improvedperformance as compared to generic agents. For instance, becauseapplication-specific data agents 142 may only handle data for a singlesoftware application, the design, operation, and performance of the dataagent 142 can be streamlined. The data agent 142 may therefore executefaster and consume less persistent storage and/or operating memory thandata agents designed to generically accommodate multiple differentsoftware applications 110.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with data agent142 and its host client computing device 102, and process the dataappropriately. For example, during a secondary copy operation, dataagent 142 may arrange or assemble the data and metadata into one or morefiles having a certain format (e.g., a particular backup or archiveformat) before transferring the file(s) to a media agent 144 or othercomponent. The file(s) may include a list of files or other metadata. Insome embodiments, a data agent 142 may be distributed between clientcomputing device 102 and storage manager 140 (and any other intermediatecomponents) or may be deployed from a remote location or its functionsapproximated by a remote process that performs some or all of thefunctions of data agent 142. In addition, a data agent 142 may performsome functions provided by media agent 144. Other embodiments may employone or more generic data agents 142 that can handle and process datafrom two or more different applications 110, or that can handle andprocess multiple data types, instead of or in addition to usingspecialized data agents 142. For example, one generic data agent 142 maybe used to back up, migrate and restore Microsoft Exchange Mailbox dataand Microsoft Exchange Database data, while another generic data agentmay handle Microsoft Exchange Public Folder data and Microsoft WindowsFile System data.

Media Agents

As noted, off-loading certain responsibilities from client computingdevices 102 to intermediate components such as secondary storagecomputing device(s) 106 and corresponding media agent(s) 144 can providea number of benefits including improved performance of client computingdevice 102, faster and more reliable information management operations,and enhanced scalability. In one example which will be discussed furtherbelow, media agent 144 can act as a local cache of recently-copied dataand/or metadata stored to secondary storage device(s) 108, thusimproving restore capabilities and performance for the cached data.

Media agent 144 is a component of system 100 and is generally directedby storage manager 140 in creating and restoring secondary copies 116.Whereas storage manager 140 generally manages system 100 as a whole,media agent 144 provides a portal to certain secondary storage devices108, such as by having specialized features for communicating with andaccessing certain associated secondary storage device 108. Media agent144 may be a software program (e.g., in the form of a set of executablebinary files) that executes on a secondary storage computing device 106.Media agent 144 generally manages, coordinates, and facilitates thetransmission of data between a data agent 142 (executing on clientcomputing device 102) and secondary storage device(s) 108 associatedwith media agent 144. For instance, other components in the system mayinteract with media agent 144 to gain access to data stored onassociated secondary storage device(s) 108, (e.g., to browse, read,write, modify, delete, or restore data). Moreover, media agents 144 cangenerate and store information relating to characteristics of the storeddata and/or metadata, or can generate and store other types ofinformation that generally provides insight into the contents of thesecondary storage devices 108—generally referred to as indexing of thestored secondary copies 116. Each media agent 144 may operate on adedicated secondary storage computing device 106, while in otherembodiments a plurality of media agents 144 may operate on the samesecondary storage computing device 106.

A media agent 144 may be associated with a particular secondary storagedevice 108 if that media agent 144 is capable of one or more of: routingand/or storing data to the particular secondary storage device 108;coordinating the routing and/or storing of data to the particularsecondary storage device 108; retrieving data from the particularsecondary storage device 108; coordinating the retrieval of data fromthe particular secondary storage device 108; and modifying and/ordeleting data retrieved from the particular secondary storage device108. Media agent 144 in certain embodiments is physically separate fromthe associated secondary storage device 108. For instance, a media agent144 may operate on a secondary storage computing device 106 in adistinct housing, package, and/or location from the associated secondarystorage device 108. In one example, a media agent 144 operates on afirst server computer and is in communication with a secondary storagedevice(s) 108 operating in a separate rack-mounted RAID-based system.

A media agent 144 associated with a particular secondary storage device108 may instruct secondary storage device 108 to perform an informationmanagement task. For instance, a media agent 144 may instruct a tapelibrary to use a robotic arm or other retrieval means to load or eject acertain storage media, and to subsequently archive, migrate, or retrievedata to or from that media, e.g., for the purpose of restoring data to aclient computing device 102. As another example, a secondary storagedevice 108 may include an array of hard disk drives or solid statedrives organized in a RAID configuration, and media agent 144 mayforward a logical unit number (LUN) and other appropriate information tothe array, which uses the received information to execute the desiredsecondary copy operation. Media agent 144 may communicate with asecondary storage device 108 via a suitable communications link, such asa SCSI or Fibre Channel link.

Each media agent 144 may maintain an associated media agent database152. Media agent database 152 may be stored to a disk or other storagedevice (not shown) that is local to the secondary storage computingdevice 106 on which media agent 144 executes. In other cases, mediaagent database 152 is stored separately from the host secondary storagecomputing device 106. Media agent database 152 can include, among otherthings, a media agent index 153 (see, e.g., FIG. 1C). In some cases,media agent index 153 does not form a part of and is instead separatefrom media agent database 152.

Media agent index 153 (or “index 153”) may be a data structureassociated with the particular media agent 144 that includes informationabout the stored data associated with the particular media agent andwhich may be generated in the course of performing a secondary copyoperation or a restore. Index 153 provides a fast and efficientmechanism for locating/browsing secondary copies 116 or other datastored in secondary storage devices 108 without having to accesssecondary storage device 108 to retrieve the information from there. Forinstance, for each secondary copy 116, index 153 may include metadatasuch as a list of the data objects (e.g., files/subdirectories, databaseobjects, mailbox objects, etc.), a logical path to the secondary copy116 on the corresponding secondary storage device 108, locationinformation (e.g., offsets) indicating where the data objects are storedin the secondary storage device 108, when the data objects were createdor modified, etc. Thus, index 153 includes metadata associated with thesecondary copies 116 that is readily available for use from media agent144. In some embodiments, some or all of the information in index 153may instead or additionally be stored along with secondary copies 116 insecondary storage device 108. In some embodiments, a secondary storagedevice 108 can include sufficient information to enable a “bare metalrestore,” where the operating system and/or software applications of afailed client computing device 102 or another target may beautomatically restored without manually reinstalling individual softwarepackages (including operating systems).

Because index 153 may operate as a cache, it can also be referred to asan “index cache.” In such cases, information stored in index cache 153typically comprises data that reflects certain particulars aboutrelatively recent secondary copy operations. After some triggeringevent, such as after some time elapses or index cache 153 reaches aparticular size, certain portions of index cache 153 may be copied ormigrated to secondary storage device 108, e.g., on a least-recently-usedbasis. This information may be retrieved and uploaded back into indexcache 153 or otherwise restored to media agent 144 to facilitateretrieval of data from the secondary storage device(s) 108. In someembodiments, the cached information may include format orcontainerization information related to archives or other files storedon storage device(s) 108.

In some alternative embodiments media agent 144 generally acts as acoordinator or facilitator of secondary copy operations between clientcomputing devices 102 and secondary storage devices 108, but does notactually write the data to secondary storage device 108. For instance,storage manager 140 (or media agent 144) may instruct a client computingdevice 102 and secondary storage device 108 to communicate with oneanother directly. In such a case, client computing device 102 transmitsdata directly or via one or more intermediary components to secondarystorage device 108 according to the received instructions, and viceversa. Media agent 144 may still receive, process, and/or maintainmetadata related to the secondary copy operations, i.e., may continue tobuild and maintain index 153. In these embodiments, payload data canflow through media agent 144 for the purposes of populating index 153,but not for writing to secondary storage device 108. Media agent 144and/or other components such as storage manager 140 may in some casesincorporate additional functionality, such as data classification,content indexing, deduplication, encryption, compression, and the like.Further details regarding these and other functions are described below.

Distributed, Scalable Architecture

As described, certain functions of system 100 can be distributed amongstvarious physical and/or logical components. For instance, one or more ofstorage manager 140, data agents 142, and media agents 144 may operateon computing devices that are physically separate from one another. Thisarchitecture can provide a number of benefits. For instance, hardwareand software design choices for each distributed component can betargeted to suit its particular function. The secondary computingdevices 106 on which media agents 144 operate can be tailored forinteraction with associated secondary storage devices 108 and providefast index cache operation, among other specific tasks. Similarly,client computing device(s) 102 can be selected to effectively serviceapplications 110 in order to efficiently produce and store primary data112.

Moreover, in some cases, one or more of the individual components ofinformation management system 100 can be distributed to multipleseparate computing devices. As one example, for large file systems wherethe amount of data stored in management database 146 is relativelylarge, database 146 may be migrated to or may otherwise reside on aspecialized database server (e.g., an SQL server) separate from a serverthat implements the other functions of storage manager 140. Thisdistributed configuration can provide added protection because database146 can be protected with standard database utilities (e.g., SQL logshipping or database replication) independent from other functions ofstorage manager 140. Database 146 can be efficiently replicated to aremote site for use in the event of a disaster or other data loss at theprimary site. Or database 146 can be replicated to another computingdevice within the same site, such as to a higher performance machine inthe event that a storage manager host computing device can no longerservice the needs of a growing system 100.

The distributed architecture also provides scalability and efficientcomponent utilization. FIG. 1D shows an embodiment of informationmanagement system 100 including a plurality of client computing devices102 and associated data agents 142 as well as a plurality of secondarystorage computing devices 106 and associated media agents 144.Additional components can be added or subtracted based on the evolvingneeds of system 100. For instance, depending on where bottlenecks areidentified, administrators can add additional client computing devices102, secondary storage computing devices 106, and/or secondary storagedevices 108. Moreover, where multiple fungible components are available,load balancing can be implemented to dynamically address identifiedbottlenecks. As an example, storage manager 140 may dynamically selectwhich media agents 144 and/or secondary storage devices 108 to use forstorage operations based on a processing load analysis of media agents144 and/or secondary storage devices 108, respectively.

Where system 100 includes multiple media agents 144 (see, e.g., FIG.1D), a first media agent 144 may provide failover functionality for asecond failed media agent 144. In addition, media agents 144 can bedynamically selected to provide load balancing. Each client computingdevice 102 can communicate with, among other components, any of themedia agents 144, e.g., as directed by storage manager 140. And eachmedia agent 144 may communicate with, among other components, any ofsecondary storage devices 108, e.g., as directed by storage manager 140.Thus, operations can be routed to secondary storage devices 108 in adynamic and highly flexible manner, to provide load balancing, failover,etc. Further examples of scalable systems capable of dynamic storageoperations, load balancing, and failover are provided in U.S. Pat. No.7,246,207.

While distributing functionality amongst multiple computing devices canhave certain advantages, in other contexts it can be beneficial toconsolidate functionality on the same computing device. In alternativeconfigurations, certain components may reside and execute on the samecomputing device. As such, in other embodiments, one or more of thecomponents shown in FIG. 1C may be implemented on the same computingdevice. In one configuration, a storage manager 140, one or more dataagents 142, and/or one or more media agents 144 are all implemented onthe same computing device. In other embodiments, one or more data agents142 and one or more media agents 144 are implemented on the samecomputing device, while storage manager 140 is implemented on a separatecomputing device, etc. without limitation.

Exemplary Types of Information Management Operations, Including StorageOperations

In order to protect and leverage stored data, system 100 can beconfigured to perform a variety of information management operations,which may also be referred to in some cases as storage managementoperations or storage operations. These operations can generally include(i) data movement operations, (ii) processing and data manipulationoperations, and (iii) analysis, reporting, and management operations.

Data Movement Operations, Including Secondary Copy Operations

Data movement operations are generally storage operations that involvethe copying or migration of data between different locations in system100. For example, data movement operations can include operations inwhich stored data is copied, migrated, or otherwise transferred from oneor more first storage devices to one or more second storage devices,such as from primary storage device(s) 104 to secondary storagedevice(s) 108, from secondary storage device(s) 108 to differentsecondary storage device(s) 108, from secondary storage devices 108 toprimary storage devices 104, or from primary storage device(s) 104 todifferent primary storage device(s) 104, or in some cases within thesame primary storage device 104 such as within a storage array.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication), snapshotoperations, deduplication or single-instancing operations, auxiliarycopy operations, disaster-recovery copy operations, and the like. Aswill be discussed, some of these operations do not necessarily createdistinct copies. Nonetheless, some or all of these operations aregenerally referred to as “secondary copy operations” for simplicity,because they involve secondary copies. Data movement also comprisesrestoring secondary copies.

Backup Operations

A backup operation creates a copy of a version of primary data 112 at aparticular point in time (e.g., one or more files or other data units).Each subsequent backup copy 116 (which is a form of secondary copy 116)may be maintained independently of the first. A backup generallyinvolves maintaining a version of the copied primary data 112 as well asbackup copies 116. Further, a backup copy in some embodiments isgenerally stored in a form that is different from the native format,e.g., a backup format. This contrasts to the version in primary data 112which may instead be stored in a format native to the sourceapplication(s) 110. In various cases, backup copies can be stored in aformat in which the data is compressed, encrypted, deduplicated, and/orotherwise modified from the original native application format. Forexample, a backup copy may be stored in a compressed backup format thatfacilitates efficient long-term storage. Backup copies 116 can haverelatively long retention periods as compared to primary data 112, whichis generally highly changeable. Backup copies 116 may be stored on mediawith slower retrieval times than primary storage device 104. Some backupcopies may have shorter retention periods than some other types ofsecondary copies 116, such as archive copies (described below). Backupsmay be stored at an offsite location.

Backup operations can include full backups, differential backups,incremental backups, “synthetic full” backups, and/or creating a“reference copy.” A full backup (or “standard full backup”) in someembodiments is generally a complete image of the data to be protected.However, because full backup copies can consume a relatively largeamount of storage, it can be useful to use a full backup copy as abaseline and only store changes relative to the full backup copyafterwards.

A differential backup operation (or cumulative incremental backupoperation) tracks and stores changes that occurred since the last fullbackup. Differential backups can grow quickly in size, but can restorerelatively efficiently because a restore can be completed in some casesusing only the full backup copy and the latest differential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restoring can be lengthycompared to full or differential backups because completing a restoreoperation may involve accessing a full backup in addition to multipleincremental backups.

Synthetic full backups generally consolidate data without directlybacking up data from the client computing device. A synthetic fullbackup is created from the most recent full backup (i.e., standard orsynthetic) and subsequent incremental and/or differential backups. Theresulting synthetic full backup is identical to what would have beencreated had the last backup for the subclient been a standard fullbackup. Unlike standard full, incremental, and differential backups,however, a synthetic full backup does not actually transfer data fromprimary storage to the backup media, because it operates as a backupconsolidator. A synthetic full backup extracts the index data of eachparticipating subclient. Using this index data and the previously backedup user data images, it builds new full backup images (e.g., bitmaps),one for each subclient. The new backup images consolidate the index anduser data stored in the related incremental, differential, and previousfull backups into a synthetic backup file that fully represents thesubclient (e.g., via pointers) but does not comprise all its constituentdata.

Any of the above types of backup operations can be at the volume level,file level, or block level. Volume level backup operations generallyinvolve copying of a data volume (e.g., a logical disk or partition) asa whole. In a file-level backup, information management system 100generally tracks changes to individual files and includes copies offiles in the backup copy. For block-level backups, files are broken intoconstituent blocks, and changes are tracked at the block level. Uponrestore, system 100 reassembles the blocks into files in a transparentfashion. Far less data may actually be transferred and copied tosecondary storage devices 108 during a file-level copy than avolume-level copy. Likewise, a block-level copy may transfer less datathan a file-level copy, resulting in faster execution. However,restoring a relatively higher-granularity copy can result in longerrestore times. For instance, when restoring a block-level copy, theprocess of locating and retrieving constituent blocks can sometimes takelonger than restoring file-level backups.

A reference copy may comprise copy(ies) of selected objects from backedup data, typically to help organize data by keeping contextualinformation from multiple sources together, and/or help retain specificdata for a longer period of time, such as for legal hold needs. Areference copy generally maintains data integrity, and when the data isrestored, it may be viewed in the same format as the source data. Insome embodiments, a reference copy is based on a specialized client,individual subclient and associated information management policies(e.g., storage policy, retention policy, etc.) that are administeredwithin system 100.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied primary data 112 and also maintaining backup copies in secondarystorage device(s) 108, they can consume significant storage capacity. Toreduce storage consumption, an archive operation according to certainembodiments creates an archive copy 116 by both copying and removingsource data. Or, seen another way, archive operations can involve movingsome or all of the source data to the archive destination. Thus, datasatisfying criteria for removal (e.g., data of a threshold age or size)may be removed from source storage. The source data may be primary data112 or a secondary copy 116, depending on the situation. As with backupcopies, archive copies can be stored in a format in which the data iscompressed, encrypted, deduplicated, and/or otherwise modified from theformat of the original application or source copy. In addition, archivecopies may be retained for relatively long periods of time (e.g., years)and, in some cases are never deleted. In certain embodiments, archivecopies may be made and kept for extended periods in order to meetcompliance regulations.

Archiving can also serve the purpose of freeing up space in primarystorage device(s) 104 and easing the demand on computational resourceson client computing device 102. Similarly, when a secondary copy 116 isarchived, the archive copy can therefore serve the purpose of freeing upspace in the source secondary storage device(s) 108. Examples of dataarchiving operations are provided in U.S. Pat. No. 7,107,298.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of primary data 112 at a givenpoint in time, and may include state and/or status information relativeto an application 110 that creates/manages primary data 112. In oneembodiment, a snapshot may generally capture the directory structure ofan object in primary data 112 such as a file or volume or other data setat a particular moment in time and may also preserve file attributes andcontents. A snapshot in some cases is created relatively quickly, e.g.,substantially instantly, using a minimum amount of file space, but maystill function as a conventional file system backup.

A “hardware snapshot” (or “hardware-based snapshot”) operation occurswhere a target storage device (e.g., a primary storage device 104 or asecondary storage device 108) performs the snapshot operation in aself-contained fashion, substantially independently, using hardware,firmware and/or software operating on the storage device itself. Forinstance, the storage device may perform snapshot operations generallywithout intervention or oversight from any of the other components ofthe system 100, e.g., a storage array may generate an “array-created”hardware snapshot and may also manage its storage, integrity,versioning, etc. In this manner, hardware snapshots can off-load othercomponents of system 100 from snapshot processing. An array may receivea request from another component to take a snapshot and then proceed toexecute the “hardware snapshot” operations autonomously, preferablyreporting success to the requesting component.

A “software snapshot” (or “software-based snapshot”) operation, on theother hand, occurs where a component in system 100 (e.g., clientcomputing device 102, etc.) implements a software layer that manages thesnapshot operation via interaction with the target storage device. Forinstance, the component executing the snapshot management software layermay derive a set of pointers and/or data that represents the snapshot.The snapshot management software layer may then transmit the same to thetarget storage device, along with appropriate instructions for writingthe snapshot. One example of a software snapshot product is MicrosoftVolume Snapshot Service (VSS), which is part of the Microsoft Windowsoperating system.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that map files and directories to specific memorylocations (e.g., to specific disk blocks) where the data resides as itexisted at the particular point in time. For example, a snapshot copymay include a set of pointers derived from the file system or from anapplication. In some other cases, the snapshot may be created at theblock-level, such that creation of the snapshot occurs without awarenessof the file system. Each pointer points to a respective stored datablock, so that collectively, the set of pointers reflect the storagelocation and state of the data object (e.g., file(s) or volume(s) ordata set(s)) at the point in time when the snapshot copy was created.

An initial snapshot may use only a small amount of disk space needed torecord a mapping or other data structure representing or otherwisetracking the blocks that correspond to the current state of the filesystem. Additional disk space is usually required only when files anddirectories change later on. Furthermore, when files change, typicallyonly the pointers which map to blocks are copied, not the blocksthemselves. For example for “copy-on-write” snapshots, when a blockchanges in primary storage, the block is copied to secondary storage orcached in primary storage before the block is overwritten in primarystorage, and the pointer to that block is changed to reflect the newlocation of that block. The snapshot mapping of file system data mayalso be updated to reflect the changed block(s) at that particular pointin time. In some other cases, a snapshot includes a full physical copyof all or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782. A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Replication Operations

Replication is another type of secondary copy operation. Some types ofsecondary copies 116 periodically capture images of primary data 112 atparticular points in time (e.g., backups, archives, and snapshots).However, it can also be useful for recovery purposes to protect primarydata 112 in a more continuous fashion, by replicating primary data 112substantially as changes occur. In some cases a replication copy can bea mirror copy, for instance, where changes made to primary data 112 aremirrored or substantially immediately copied to another location (e.g.,to secondary storage device(s) 108). By copying each write operation tothe replication copy, two storage systems are kept synchronized orsubstantially synchronized so that they are virtually identical atapproximately the same time. Where entire disk volumes are mirrored,however, mirroring can require significant amount of storage space andutilizes a large amount of processing resources.

According to some embodiments, secondary copy operations are performedon replicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, back up, or otherwise manipulate thereplication copies as if they were the “live” primary data 112. This canreduce access time, storage utilization, and impact on sourceapplications 110, among other benefits. Based on known good stateinformation, system 100 can replicate sections of application data thatrepresent a recoverable state rather than rote copying of blocks ofdata. Examples of replication operations (e.g., continuous datareplication) are provided in U.S. Pat. No. 7,617,262.

Deduplication/Single-Instancing Operations

Deduplication or single-instance storage is useful to reduce the amountof non-primary data. For instance, some or all of the above-describedsecondary copy operations can involve deduplication in some fashion. Newdata is read, broken down into data portions of a selected granularity(e.g., sub-file level blocks, files, etc.), compared with correspondingportions that are already in secondary storage, and only new/changedportions are stored. Portions that already exist are represented aspointers to the already-stored data. Thus, a deduplicated secondary copy116 may comprise actual data portions copied from primary data 112 andmay further comprise pointers to already-stored data, which is generallymore storage-efficient than a full copy.

In order to streamline the comparison process, system 100 may calculateand/or store signatures (e.g., hashes or cryptographically unique IDs)corresponding to the individual source data portions and compare thesignatures to already-stored data signatures, instead of comparingentire data portions. In some cases, only a single instance of each dataportion is stored, and deduplication operations may therefore bereferred to interchangeably as “single-instancing” operations. Dependingon the implementation, however, deduplication operations can store morethan one instance of certain data portions, yet still significantlyreduce stored-data redundancy. Depending on the embodiment,deduplication portions such as data blocks can be of fixed or variablelength. Using variable length blocks can enhance deduplication byresponding to changes in the data stream, but can involve more complexprocessing. In some cases, system 100 utilizes a technique fordynamically aligning deduplication blocks based on changing content inthe data stream, as described in U.S. Pat. No. 8,364,652.

System 100 can deduplicate in a variety of manners at a variety oflocations. For instance, in some embodiments, system 100 implements“target-side” deduplication by deduplicating data at the media agent 144after being received from data agent 142. In some such cases, mediaagents 144 are generally configured to manage the deduplication process.For instance, one or more of the media agents 144 maintain acorresponding deduplication database that stores deduplicationinformation (e.g., datablock signatures). Examples of such aconfiguration are provided in U.S. Pat. No. 9,020,900. Instead of or incombination with “target-side” deduplication, “source-side” (or“client-side”) deduplication can also be performed, e.g., to reduce theamount of data to be transmitted by data agent 142 to media agent 144.Storage manager 140 may communicate with other components within system100 via network protocols and cloud service provider APIs to facilitatecloud-based deduplication/single instancing, as exemplified in U.S. Pat.No. 8,954,446. Some other deduplication/single instancing techniques aredescribed in U.S. Pat. Pub. No. 2006/0224846 and in U.S. Pat. No.9,098,495.

Information Lifecycle Management and Hierarchical Storage Management

In some embodiments, files and other data over their lifetime move frommore expensive quick-access storage to less expensive slower-accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation, which generally automatically moves data between classes ofstorage devices, such as from high-cost to low-cost storage devices. Forinstance, an HSM operation may involve movement of data from primarystorage devices 104 to secondary storage devices 108, or between tiersof secondary storage devices 108. With each tier, the storage devicesmay be progressively cheaper, have relatively slower access/restoretimes, etc. For example, movement of data between tiers may occur asdata becomes less important over time. In some embodiments, an HSMoperation is similar to archiving in that creating an HSM copy may(though not always) involve deleting some of the source data, e.g.,according to one or more criteria related to the source data. Forexample, an HSM copy may include primary data 112 or a secondary copy116 that exceeds a given size threshold or a given age threshold. Often,and unlike some types of archive copies, HSM data that is removed oraged from the source is replaced by a logical reference pointer or stub.The reference pointer or stub can be stored in the primary storagedevice 104 or other source storage device, such as a secondary storagedevice 108 to replace the deleted source data and to point to orotherwise indicate the new location in (another) secondary storagedevice 108.

For example, files are generally moved between higher and lower coststorage depending on how often the files are accessed. When a userrequests access to HSM data that has been removed or migrated, system100 uses the stub to locate the data and may make recovery of the dataappear transparent, even though the HSM data may be stored at a locationdifferent from other source data. In this manner, the data appears tothe user (e.g., in file system browsing windows and the like) as if itstill resides in the source location (e.g., in a primary storage device104). The stub may include metadata associated with the correspondingdata, so that a file system and/or application can provide someinformation about the data object and/or a limited-functionality version(e.g., a preview) of the data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., compressed, encrypted, deduplicated, and/or otherwisemodified). In some cases, copies which involve the removal of data fromsource storage and the maintenance of stub or other logical referenceinformation on source storage may be referred to generally as “onlinearchive copies.” On the other hand, copies which involve the removal ofdata from source storage without the maintenance of stub or otherlogical reference information on source storage may be referred to as“off-line archive copies.” Examples of HSM and ILM techniques areprovided in U.S. Pat. No. 7,343,453.

Auxiliary Copy Operations

An auxiliary copy is generally a copy of an existing secondary copy 116.For instance, an initial secondary copy 116 may be derived from primarydata 112 or from data residing in secondary storage subsystem 118,whereas an auxiliary copy is generated from the initial secondary copy116. Auxiliary copies provide additional standby copies of data and mayreside on different secondary storage devices 108 than the initialsecondary copies 116. Thus, auxiliary copies can be used for recoverypurposes if initial secondary copies 116 become unavailable. Exemplaryauxiliary copy techniques are described in further detail in U.S. Pat.No. 8,230,195.

Disaster-Recovery Copy Operations

System 100 may also make and retain disaster recovery copies, often assecondary, high-availability disk copies. System 100 may createsecondary copies and store them at disaster recovery locations usingauxiliary copy or replication operations, such as continuous datareplication technologies. Depending on the particular data protectiongoals, disaster recovery locations can be remote from the clientcomputing devices 102 and primary storage devices 104, remote from someor all of the secondary storage devices 108, or both.

Data Manipulation, Including Encryption and Compression

Data manipulation and processing may include encryption and compressionas well as integrity marking and checking, formatting for transmission,formatting for storage, etc. Data may be manipulated “client-side” bydata agent 142 as well as “target-side” by media agent 144 in the courseof creating secondary copy 116, or conversely in the course of restoringdata from secondary to primary.

Encryption Operations

System 100 in some cases is configured to process data (e.g., files orother data objects, primary data 112, secondary copies 116, etc.),according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard (AES), Triple Data Encryption Standard(3-DES), etc.) to limit access and provide data security. System 100 insome cases encrypts the data at the client level, such that clientcomputing devices 102 (e.g., data agents 142) encrypt the data prior totransferring it to other components, e.g., before sending the data tomedia agents 144 during a secondary copy operation. In such cases,client computing device 102 may maintain or have access to an encryptionkey or passphrase for decrypting the data upon restore. Encryption canalso occur when media agent 144 creates auxiliary copies or archivecopies. Encryption may be applied in creating a secondary copy 116 of apreviously unencrypted secondary copy 116, without limitation. Infurther embodiments, secondary storage devices 108 can implementbuilt-in, high performance hardware-based encryption.

Compression Operations

Similar to encryption, system 100 may also or alternatively compressdata in the course of generating a secondary copy 116. Compressionencodes information such that fewer bits are needed to represent theinformation as compared to the original representation. Compressiontechniques are well known in the art. Compression operations may applyone or more data compression algorithms. Compression may be applied increating a secondary copy 116 of a previously uncompressed secondarycopy, e.g., when making archive copies or disaster recovery copies. Theuse of compression may result in metadata that specifies the nature ofthe compression, so that data may be uncompressed on restore ifappropriate.

Data Analysis, Reporting, and Management Operations

Data analysis, reporting, and management operations can differ from datamovement operations in that they do not necessarily involve copying,migration or other transfer of data between different locations in thesystem. For instance, data analysis operations may involve processing(e.g., offline processing) or modification of already stored primarydata 112 and/or secondary copies 116. However, in some embodiments dataanalysis operations are performed in conjunction with data movementoperations. Some data analysis operations include content indexingoperations and classification operations which can be useful inleveraging data under management to enhance search and other features.

Classification Operations/Content Indexing

In some embodiments, information management system 100 analyzes andindexes characteristics, content, and metadata associated with primarydata 112 (“online content indexing”) and/or secondary copies 116(“off-line content indexing”). Content indexing can identify files orother data objects based on content (e.g., user-defined keywords orphrases, other keywords/phrases that are not defined by a user, etc.),and/or metadata (e.g., email metadata such as “to,” “from,” “cc,” “bcc,”attachment name, received time, etc.). Content indexes may be searchedand search results may be restored.

System 100 generally organizes and catalogues the results into a contentindex, which may be stored within media agent database 152, for example.The content index can also include the storage locations of or pointerreferences to indexed data in primary data 112 and/or secondary copies116. Results may also be stored elsewhere in system 100 (e.g., inprimary storage device 104 or in secondary storage device 108). Suchcontent index data provides storage manager 140 or other components withan efficient mechanism for locating primary data 112 and/or secondarycopies 116 of data objects that match particular criteria, thus greatlyincreasing the search speed capability of system 100. For instance,search criteria can be specified by a user through user interface 158 ofstorage manager 140. Moreover, when system 100 analyzes data and/ormetadata in secondary copies 116 to create an “off-line content index,”this operation has no significant impact on the performance of clientcomputing devices 102 and thus does not take a toll on the productionenvironment. Examples of content indexing techniques are provided inU.S. Pat. No. 8,170,995.

One or more components, such as a content index engine, can beconfigured to scan data and/or associated metadata for classificationpurposes to populate a database (or other data structure) ofinformation, which can be referred to as a “data classificationdatabase” or a “metabase.” Depending on the embodiment, the dataclassification database(s) can be organized in a variety of differentways, including centralization, logical sub-divisions, and/or physicalsub-divisions. For instance, one or more data classification databasesmay be associated with different subsystems or tiers within system 100.As an example, there may be a first metabase associated with primarystorage subsystem 117 and a second metabase associated with secondarystorage subsystem 118. In other cases, metabase(s) may be associatedwith individual components, e.g., client computing devices 102 and/ormedia agents 144. In some embodiments, a data classification databasemay reside as one or more data structures within management database146, may be otherwise associated with storage manager 140, and/or mayreside as a separate component. In some cases, metabase(s) may beincluded in separate database(s) and/or on separate storage device(s)from primary data 112 and/or secondary copies 116, such that operationsrelated to the metabase(s) do not significantly impact performance onother components of system 100. In other cases, metabase(s) may bestored along with primary data 112 and/or secondary copies 116. Files orother data objects can be associated with identifiers (e.g., tagentries, etc.) to facilitate searches of stored data objects. Among anumber of other benefits, the metabase can also allow efficient,automatic identification of files or other data objects to associatewith secondary copy or other information management operations. Forinstance, a metabase can dramatically improve the speed with whichsystem 100 can search through and identify data as compared to otherapproaches that involve scanning an entire file system. Examples ofmetabases and data classification operations are provided in U.S. Pat.Nos. 7,734,669 and 7,747,579.

Management and Reporting Operations

Certain embodiments leverage the integrated ubiquitous nature of system100 to provide useful system-wide management and reporting. Operationsmanagement can generally include monitoring and managing the health andperformance of system 100 by, without limitation, performing errortracking, generating granular storage/performance metrics (e.g., jobsuccess/failure information, deduplication efficiency, etc.), generatingstorage modeling and costing information, and the like. As an example,storage manager 140 or another component in system 100 may analyzetraffic patterns and suggest and/or automatically route data to minimizecongestion. In some embodiments, the system can generate predictionsrelating to storage operations or storage operation information. Suchpredictions, which may be based on a trending analysis, may predictvarious network operations or resource usage, such as network trafficlevels, storage media use, use of bandwidth of communication links, useof media agent components, etc. Further examples of traffic analysis,trend analysis, prediction generation, and the like are described inU.S. Pat. No. 7,343,453.

In some configurations having a hierarchy of storage operation cells, amaster storage manager 140 may track the status of subordinate cells,such as the status of jobs, system components, system resources, andother items, by communicating with storage managers 140 (or othercomponents) in the respective storage operation cells. Moreover, themaster storage manager 140 may also track status by receiving periodicstatus updates from the storage managers 140 (or other components) inthe respective cells regarding jobs, system components, systemresources, and other items. In some embodiments, a master storagemanager 140 may store status information and other information regardingits associated storage operation cells and other system information inits management database 146 and/or index 150 (or in another location).The master storage manager 140 or other component may also determinewhether certain storage-related or other criteria are satisfied, and mayperform an action or trigger event (e.g., data migration) in response tothe criteria being satisfied, such as where a storage threshold is metfor a particular volume, or where inadequate protection exists forcertain data. For instance, data from one or more storage operationcells is used to dynamically and automatically mitigate recognizedrisks, and/or to advise users of risks or suggest actions to mitigatethese risks. For example, an information management policy may specifycertain requirements (e.g., that a storage device should maintain acertain amount of free space, that secondary copies should occur at aparticular interval, that data should be aged and migrated to otherstorage after a particular period, that data on a secondary volumeshould always have a certain level of availability and be restorablewithin a given time period, that data on a secondary volume may bemirrored or otherwise migrated to a specified number of other volumes,etc.). If a risk condition or other criterion is triggered, the systemmay notify the user of these conditions and may suggest (orautomatically implement) a mitigation action to address the risk. Forexample, the system may indicate that data from a primary copy 112should be migrated to a secondary storage device 108 to free up space onprimary storage device 104. Examples of the use of risk factors andother triggering criteria are described in U.S. Pat. No. 7,343,453.

In some embodiments, system 100 may also determine whether a metric orother indication satisfies particular storage criteria sufficient toperform an action. For example, a storage policy or other definitionmight indicate that a storage manager 140 should initiate a particularaction if a storage metric or other indication drops below or otherwisefails to satisfy specified criteria such as a threshold of dataprotection. In some embodiments, risk factors may be quantified intocertain measurable service or risk levels. For example, certainapplications and associated data may be considered to be more importantrelative to other data and services. Financial compliance data, forexample, may be of greater importance than marketing materials, etc.Network administrators may assign priority values or “weights” tocertain data and/or applications corresponding to the relativeimportance. The level of compliance of secondary copy operationsspecified for these applications may also be assigned a certain value.Thus, the health, impact, and overall importance of a service may bedetermined, such as by measuring the compliance value and calculatingthe product of the priority value and the compliance value to determinethe “service level” and comparing it to certain operational thresholdsto determine whether it is acceptable. Further examples of the servicelevel determination are provided in U.S. Pat. No. 7,343,453.

System 100 may additionally calculate data costing and data availabilityassociated with information management operation cells. For instance,data received from a cell may be used in conjunction withhardware-related information and other information about system elementsto determine the cost of storage and/or the availability of particulardata. Exemplary information generated could include how fast aparticular department is using up available storage space, how long datawould take to recover over a particular pathway from a particularsecondary storage device, costs over time, etc. Moreover, in someembodiments, such information may be used to determine or predict theoverall cost associated with the storage of certain information. Thecost associated with hosting a certain application may be based, atleast in part, on the type of media on which the data resides, forexample. Storage devices may be assigned to a particular costcategories, for example. Further examples of costing techniques aredescribed in U.S. Pat. No. 7,343,453.

Any of the above types of information (e.g., information related totrending, predictions, job, cell or component status, risk, servicelevel, costing, etc.) can generally be provided to users via userinterface 158 in a single integrated view or console (not shown). Reporttypes may include: scheduling, event management, media management anddata aging. Available reports may also include backup history, dataaging history, auxiliary copy history, job history, library and drive,media in library, restore history, and storage policy, etc., withoutlimitation. Such reports may be specified and created at a certain pointin time as a system analysis, forecasting, or provisioning tool.Integrated reports may also be generated that illustrate storage andperformance metrics, risks and storage costing information. Moreover,users may create their own reports based on specific needs. Userinterface 158 can include an option to graphically depict the variouscomponents in the system using appropriate icons. As one example, userinterface 158 may provide a graphical depiction of primary storagedevices 104, secondary storage devices 108, data agents 142 and/or mediaagents 144, and their relationship to one another in system 100.

In general, the operations management functionality of system 100 canfacilitate planning and decision-making. For example, in someembodiments, a user may view the status of some or all jobs as well asthe status of each component of information management system 100. Usersmay then plan and make decisions based on this data. For instance, auser may view high-level information regarding secondary copy operationsfor system 100, such as job status, component status, resource status(e.g., communication pathways, etc.), and other information. The usermay also drill down or use other means to obtain more detailedinformation regarding a particular component, job, or the like. Furtherexamples are provided in U.S. Pat. No. 7,343,453.

System 100 can also be configured to perform system-wide e-discoveryoperations in some embodiments. In general, e-discovery operationsprovide a unified collection and search capability for data in thesystem, such as data stored in secondary storage devices 108 (e.g.,backups, archives, or other secondary copies 116). For example, system100 may construct and maintain a virtual repository for data stored insystem 100 that is integrated across source applications 110, differentstorage device types, etc. According to some embodiments, e-discoveryutilizes other techniques described herein, such as data classificationand/or content indexing.

Information Management Policies

An information management policy 148 can include a data structure orother information source that specifies a set of parameters (e.g.,criteria and rules) associated with secondary copy and/or otherinformation management operations.

One type of information management policy 148 is a “storage policy.”According to certain embodiments, a storage policy generally comprises adata structure or other information source that defines (or includesinformation sufficient to determine) a set of preferences or othercriteria for performing information management operations. Storagepolicies can include one or more of the following: (1) what data will beassociated with the storage policy, e.g., subclient; (2) a destinationto which the data will be stored; (3) datapath information specifyinghow the data will be communicated to the destination; (4) the type ofsecondary copy operation to be performed; and (5) retention informationspecifying how long the data will be retained at the destination (see,e.g., FIG. 1E). Data associated with a storage policy can be logicallyorganized into subclients, which may represent primary data 112 and/orsecondary copies 116. A subclient may represent static or dynamicassociations of portions of a data volume. Subclients may representmutually exclusive portions. Thus, in certain embodiments, a portion ofdata may be given a label and the association is stored as a staticentity in an index, database or other storage location. Subclients mayalso be used as an effective administrative scheme of organizing dataaccording to data type, department within the enterprise, storagepreferences, or the like. Depending on the configuration, subclients cancorrespond to files, folders, virtual machines, databases, etc. In oneexemplary scenario, an administrator may find it preferable to separatee-mail data from financial data using two different subclients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the subclients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the subclients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesubclient data. While information in the storage policy can bestatically assigned in some cases, some or all of the information in thestorage policy can also be dynamically determined based on criteria setforth in the storage policy. For instance, based on such criteria, aparticular destination storage device(s) or other parameter of thestorage policy may be determined based on characteristics associatedwith the data involved in a particular secondary copy operation, deviceavailability (e.g., availability of a secondary storage device 108 or amedia agent 144), network status and conditions (e.g., identifiedbottlenecks), user credentials, and the like.

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data associated with the storage policy between thesource and destination. A storage policy can also specify the type(s) ofassociated operations, such as backup, archive, snapshot, auxiliarycopy, or the like. Furthermore, retention parameters can specify howlong the resulting secondary copies 116 will be kept (e.g., a number ofdays, months, years, etc.), perhaps depending on organizational needsand/or compliance criteria.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via user interface 158. However, this can be an involvedprocess resulting in delays, and it may be desirable to begin dataprotection operations quickly, without awaiting human intervention.Thus, in some embodiments, system 100 automatically applies a defaultconfiguration to client computing device 102. As one example, when oneor more data agent(s) 142 are installed on a client computing device102, the installation script may register the client computing device102 with storage manager 140, which in turn applies the defaultconfiguration to the new client computing device 102. In this manner,data protection operations can begin substantially immediately. Thedefault configuration can include a default storage policy, for example,and can specify any appropriate information sufficient to begin dataprotection operations. This can include a type of data protectionoperation, scheduling information, a target secondary storage device108, data path information (e.g., a particular media agent 144), and thelike.

Another type of information management policy 148 is a “schedulingpolicy,” which specifies when and how often to perform operations.Scheduling parameters may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations are to takeplace. Scheduling policies in some cases are associated with particularcomponents, such as a subclient, client computing device 102, and thelike.

Another type of information management policy 148 is an “audit policy”(or “security policy”), which comprises preferences, rules and/orcriteria that protect sensitive data in system 100. For example, anaudit policy may define “sensitive objects” which are files or dataobjects that contain particular keywords (e.g., “confidential,” or“privileged”) and/or are associated with particular keywords (e.g., inmetadata) or particular flags (e.g., in metadata identifying a documentor email as personal, confidential, etc.). An audit policy may furtherspecify rules for handling sensitive objects. As an example, an auditpolicy may require that a reviewer approve the transfer of any sensitiveobjects to a cloud storage site, and that if approval is denied for aparticular sensitive object, the sensitive object should be transferredto a local primary storage device 104 instead. To facilitate thisapproval, the audit policy may further specify how a secondary storagecomputing device 106 or other system component should notify a reviewerthat a sensitive object is slated for transfer.

Another type of information management policy 148 is a “provisioningpolicy,” which can include preferences, priorities, rules, and/orcriteria that specify how client computing devices 102 (or groupsthereof) may utilize system resources, such as available storage oncloud storage and/or network bandwidth. A provisioning policy specifies,for example, data quotas for particular client computing devices 102(e.g., a number of gigabytes that can be stored monthly, quarterly orannually). Storage manager 140 or other components may enforce theprovisioning policy. For instance, media agents 144 may enforce thepolicy when transferring data to secondary storage devices 108. If aclient computing device 102 exceeds a quota, a budget for the clientcomputing device 102 (or associated department) may be adjustedaccordingly or an alert may trigger.

While the above types of information management policies 148 aredescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies or operationalparameters thereof. Moreover, while storage policies are typicallyassociated with moving and storing data, other policies may beassociated with other types of information management operations. Thefollowing is a non-exhaustive list of items that information managementpolicies 148 may specify:

-   -   schedules or other timing information, e.g., specifying when        and/or how often to perform information management operations;    -   the type of secondary copy 116 and/or copy format (e.g.,        snapshot, backup, archive, HSM, etc.);    -   a location or a class or quality of storage for storing        secondary copies 116 (e.g., one or more particular secondary        storage devices 108);    -   preferences regarding whether and how to encrypt, compress,        deduplicate, or otherwise modify or transform secondary copies        116;    -   which system components and/or network pathways (e.g., preferred        media agents 144) should be used to perform secondary storage        operations;    -   resource allocation among different computing devices or other        system components used in performing information management        operations (e.g., bandwidth allocation, available storage        capacity, etc.);    -   whether and how to synchronize or otherwise distribute files or        other data objects across multiple computing devices or hosted        services; and    -   retention information specifying the length of time primary data        112 and/or secondary copies 116 should be retained, e.g., in a        particular class or tier of storage devices, or within the        system 100.

Information management policies 148 can additionally specify or dependon historical or current criteria that may be used to determine whichrules to apply to a particular data object, system component, orinformation management operation, such as:

-   -   frequency with which primary data 112 or a secondary copy 116 of        a data object or metadata has been or is predicted to be used,        accessed, or modified;    -   time-related factors (e.g., aging information such as time since        the creation or modification of a data object);    -   deduplication information (e.g., hashes, data blocks,        deduplication block size, deduplication efficiency or other        metrics);    -   an estimated or historic usage or cost associated with different        components (e.g., with secondary storage devices 108);    -   the identity of users, applications 110, client computing        devices 102 and/or other computing devices that created,        accessed, modified, or otherwise utilized primary data 112 or        secondary copies 116;    -   a relative sensitivity (e.g., confidentiality, importance) of a        data object, e.g., as determined by its content and/or metadata;    -   the current or historical storage capacity of various storage        devices;    -   the current or historical network capacity of network pathways        connecting various components within the storage operation cell;    -   access control lists or other security information; and    -   the content of a particular data object (e.g., its textual        content) or of metadata associated with the data object.

Exemplary Storage Policy and Secondary Copy Operations

FIG. 1E includes a data flow diagram depicting performance of secondarycopy operations by an embodiment of information management system 100,according to an exemplary storage policy 148A. System 100 includes astorage manager 140, a client computing device 102 having a file systemdata agent 142A and an email data agent 142B operating thereon, aprimary storage device 104, two media agents 144A, 144B, and twosecondary storage devices 108: a disk library 108A and a tape library108B. As shown, primary storage device 104 includes primary data 112A,which is associated with a logical grouping of data associated with afile system (“file system subclient”), and primary data 112B, which is alogical grouping of data associated with email (“email subclient”). Thetechniques described with respect to FIG. 1E can be utilized inconjunction with data that is otherwise organized as well.

As indicated by the dashed box, the second media agent 144B and tapelibrary 108B are “off-site,” and may be remotely located from the othercomponents in system 100 (e.g., in a different city, office building,etc.). Indeed, “off-site” may refer to a magnetic tape located in remotestorage, which must be manually retrieved and loaded into a tape driveto be read. In this manner, information stored on the tape library 108Bmay provide protection in the event of a disaster or other failure atthe main site(s) where data is stored.

The file system subclient 112A in certain embodiments generallycomprises information generated by the file system and/or operatingsystem of client computing device 102, and can include, for example,file system data (e.g., regular files, file tables, mount points, etc.),operating system data (e.g., registries, event logs, etc.), and thelike. The e-mail subclient 112B can include data generated by an e-mailapplication operating on client computing device 102, e.g., mailboxinformation, folder information, emails, attachments, associateddatabase information, and the like. As described above, the subclientscan be logical containers, and the data included in the correspondingprimary data 112A and 112B may or may not be stored contiguously.

The exemplary storage policy 148A includes backup copy preferences orrule set 160, disaster recovery copy preferences or rule set 162, andcompliance copy preferences or rule set 164. Backup copy rule set 160specifies that it is associated with file system subclient 166 and emailsubclient 168. Each of subclients 166 and 168 are associated with theparticular client computing device 102. Backup copy rule set 160 furtherspecifies that the backup operation will be written to disk library 108Aand designates a particular media agent 144A to convey the data to disklibrary 108A. Finally, backup copy rule set 160 specifies that backupcopies created according to rule set 160 are scheduled to be generatedhourly and are to be retained for 30 days. In some other embodiments,scheduling information is not included in storage policy 148A and isinstead specified by a separate scheduling policy.

Disaster recovery copy rule set 162 is associated with the same twosubclients 166 and 168. However, disaster recovery copy rule set 162 isassociated with tape library 108B, unlike backup copy rule set 160.Moreover, disaster recovery copy rule set 162 specifies that a differentmedia agent, namely 144B, will convey data to tape library 108B.Disaster recovery copies created according to rule set 162 will beretained for 60 days and will be generated daily. Disaster recoverycopies generated according to disaster recovery copy rule set 162 canprovide protection in the event of a disaster or other catastrophic dataloss that would affect the backup copy 116A maintained on disk library108A.

Compliance copy rule set 164 is only associated with the email subclient168, and not the file system subclient 166. Compliance copies generatedaccording to compliance copy rule set 164 will therefore not includeprimary data 112A from the file system subclient 166. For instance, theorganization may be under an obligation to store and maintain copies ofemail data for a particular period of time (e.g., 10 years) to complywith state or federal regulations, while similar regulations do notapply to file system data. Compliance copy rule set 164 is associatedwith the same tape library 108B and media agent 144B as disasterrecovery copy rule set 162, although a different storage device or mediaagent could be used in other embodiments. Finally, compliance copy ruleset 164 specifies that the copies it governs will be generated quarterlyand retained for 10 years.

Secondary Copy Jobs

A logical grouping of secondary copy operations governed by a rule setand being initiated at a point in time may be referred to as a“secondary copy job” (and sometimes may be called a “backup job,” eventhough it is not necessarily limited to creating only backup copies).Secondary copy jobs may be initiated on demand as well. Steps 1-9 belowillustrate three secondary copy jobs based on storage policy 148A.

Referring to FIG. 1E, at step 1, storage manager 140 initiates a backupjob according to the backup copy rule set 160, which logically comprisesall the secondary copy operations necessary to effectuate rules 160 instorage policy 148A every hour, including steps 1-4 occurring hourly.For instance, a scheduling service running on storage manager 140accesses backup copy rule set 160 or a separate scheduling policyassociated with client computing device 102 and initiates a backup jobon an hourly basis. Thus, at the scheduled time, storage manager 140sends instructions to client computing device 102 (i.e., to both dataagent 142A and data agent 142B) to begin the backup job.

At step 2, file system data agent 142A and email data agent 142B onclient computing device 102 respond to instructions from storage manager140 by accessing and processing the respective subclient primary data112A and 112B involved in the backup copy operation, which can be foundin primary storage device 104. Because the secondary copy operation is abackup copy operation, the data agent(s) 142A, 142B may format the datainto a backup format or otherwise process the data suitable for a backupcopy.

At step 3, client computing device 102 communicates the processed filesystem data (e.g., using file system data agent 142A) and the processedemail data (e.g., using email data agent 142B) to the first media agent144A according to backup copy rule set 160, as directed by storagemanager 140. Storage manager 140 may further keep a record in managementdatabase 146 of the association between media agent 144A and one or moreof: client computing device 102, file system subclient 112A, file systemdata agent 142A, email subclient 112B, email data agent 142B, and/orbackup copy 116A.

The target media agent 144A receives the data-agent-processed data fromclient computing device 102, and at step 4 generates and conveys backupcopy 116A to disk library 108A to be stored as backup copy 116A, againat the direction of storage manager 140 and according to backup copyrule set 160. Media agent 144A can also update its index 153 to includedata and/or metadata related to backup copy 116A, such as informationindicating where the backup copy 116A resides on disk library 108A,where the email copy resides, where the file system copy resides, dataand metadata for cache retrieval, etc. Storage manager 140 may similarlyupdate its index 150 to include information relating to the secondarycopy operation, such as information relating to the type of operation, aphysical location associated with one or more copies created by theoperation, the time the operation was performed, status informationrelating to the operation, the components involved in the operation, andthe like. In some cases, storage manager 140 may update its index 150 toinclude some or all of the information stored in index 153 of mediaagent 144A. At this point, the backup job may be considered complete.After the 30-day retention period expires, storage manager 140 instructsmedia agent 144A to delete backup copy 116A from disk library 108A andindexes 150 and/or 153 are updated accordingly.

At step 5, storage manager 140 initiates another backup job for adisaster recovery copy according to the disaster recovery rule set 162.This includes steps 5-7 occurring daily for creating disaster recoverycopy 116B. By way of illustrating the scalable aspects and off-loadingprinciples embedded in system 100, disaster recovery copy 116B is basedon backup copy 116A and not on primary data 112A and 112B.

At step 6, based on instructions received from storage manager 140 atstep 5, the specified media agent 144B retrieves the most recent backupcopy 116A from disk library 108A.

At step 7, again at the direction of storage manager 140 and asspecified in disaster recovery copy rule set 162, media agent 144B usesthe retrieved data to create a disaster recovery copy 116B and store itto tape library 108B. In some cases, disaster recovery copy 116B is adirect, mirror copy of backup copy 116A, and remains in the backupformat. In other embodiments, disaster recovery copy 116B may be furthercompressed or encrypted, or may be generated in some other manner, suchas by using primary data 112A and 112B from primary storage device 104as sources. The disaster recovery copy operation is initiated once a dayand disaster recovery copies 116B are deleted after 60 days; indexes 153and/or 150 are updated accordingly when/after each informationmanagement operation is executed and/or completed. The present backupjob may be considered completed.

At step 8, storage manager 140 initiates another backup job according tocompliance rule set 164, which performs steps 8-9 quarterly to createcompliance copy 116C. For instance, storage manager 140 instructs mediaagent 144B to create compliance copy 116C on tape library 108B, asspecified in the compliance copy rule set 164.

At step 9 in the example, compliance copy 116C is generated usingdisaster recovery copy 116B as the source. This is efficient, becausedisaster recovery copy resides on the same secondary storage device andthus no network resources are required to move the data. In otherembodiments, compliance copy 116C is instead generated using primarydata 112B corresponding to the email subclient or using backup copy 116Afrom disk library 108A as source data. As specified in the illustratedexample, compliance copies 116C are created quarterly, and are deletedafter ten years, and indexes 153 and/or 150 are kept up-to-dateaccordingly.

Exemplary Applications of Storage Policies—Information GovernancePolicies and Classification

Again referring to FIG. 1E, storage manager 140 may permit a user tospecify aspects of storage policy 148A. For example, the storage policycan be modified to include information governance policies to define howdata should be managed in order to comply with a certain regulation orbusiness objective. The various policies may be stored, for example, inmanagement database 146. An information governance policy may align withone or more compliance tasks that are imposed by regulations or businessrequirements. Examples of information governance policies might includea Sarbanes-Oxley policy, a HIPAA policy, an electronic discovery(e-discovery) policy, and so on.

Information governance policies allow administrators to obtain differentperspectives on an organization's online and offline data, without theneed for a dedicated data silo created solely for each differentviewpoint. As described previously, the data storage systems hereinbuild an index that reflects the contents of a distributed data set thatspans numerous clients and storage devices, including both primary dataand secondary copies, and online and offline copies. An organization mayapply multiple information governance policies in a top-down manner overthat unified data set and indexing schema in order to view andmanipulate the data set through different lenses, each of which isadapted to a particular compliance or business goal. Thus, for example,by applying an e-discovery policy and a Sarbanes-Oxley policy, twodifferent groups of users in an organization can conduct two verydifferent analyses of the same underlying physical set of data/copies,which may be distributed throughout the information management system.

An information governance policy may comprise a classification policy,which defines a taxonomy of classification terms or tags relevant to acompliance task and/or business objective. A classification policy mayalso associate a defined tag with a classification rule. Aclassification rule defines a particular combination of criteria, suchas users who have created, accessed or modified a document or dataobject; file or application types; content or metadata keywords; clientsor storage locations; dates of data creation and/or access; reviewstatus or other status within a workflow (e.g., reviewed orun-reviewed); modification times or types of modifications; and/or anyother data attributes in any combination, without limitation. Aclassification rule may also be defined using other classification tagsin the taxonomy. The various criteria used to define a classificationrule may be combined in any suitable fashion, for example, via Booleanoperators, to define a complex classification rule. As an example, ane-discovery classification policy might define a classification tag“privileged” that is associated with documents or data objects that (1)were created or modified by legal department staff, or (2) were sent toor received from outside counsel via email, or (3) contain one of thefollowing keywords: “privileged” or “attorney” or “counsel,” or otherlike terms. Accordingly, all these documents or data objects will beclassified as “privileged.”

One specific type of classification tag, which may be added to an indexat the time of indexing, is an “entity tag.” An entity tag may be, forexample, any content that matches a defined data mask format. Examplesof entity tags might include, e.g., social security numbers (e.g., anynumerical content matching the formatting mask XXX-XX-XXXX), credit cardnumbers (e.g., content having a 13-16 digit string of numbers), SKUnumbers, product numbers, etc. A user may define a classification policyby indicating criteria, parameters or descriptors of the policy via agraphical user interface, such as a form or page with fields to befilled in, pull-down menus or entries allowing one or more of severaloptions to be selected, buttons, sliders, hypertext links or other knownuser interface tools for receiving user input, etc. For example, a usermay define certain entity tags, such as a particular product number orproject ID. In some implementations, the classification policy can beimplemented using cloud-based techniques. For example, the storagedevices may be cloud storage devices, and the storage manager 140 mayexecute cloud service provider API over a network to classify datastored on cloud storage devices.

Restore Operations from Secondary Copies

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of secondary copies116A, 116B, and 116C. A restore operation logically takes a selectedsecondary copy 116, reverses the effects of the secondary copy operationthat created it, and stores the restored data to primary storage where aclient computing device 102 may properly access it as primary data. Amedia agent 144 and an appropriate data agent 142 (e.g., executing onthe client computing device 102) perform the tasks needed to complete arestore operation. For example, data that was encrypted, compressed,and/or deduplicated in the creation of secondary copy 116 will becorrespondingly rehydrated (reversing deduplication), uncompressed, andunencrypted into a format appropriate to primary data. Metadata storedwithin or associated with the secondary copy 116 may be used during therestore operation. In general, restored data should be indistinguishablefrom other primary data 112. Preferably, the restored data has fullyregained the native format that may make it immediately usable byapplication 110.

As one example, a user may manually initiate a restore of backup copy116A, e.g., by interacting with user interface 158 of storage manager140 or with a web-based console with access to system 100. Storagemanager 140 may accesses data in its index 150 and/or managementdatabase 146 (and/or the respective storage policy 148A) associated withthe selected backup copy 116A to identify the appropriate media agent144A and/or secondary storage device 108A where the secondary copyresides. The user may be presented with a representation (e.g., stub,thumbnail, listing, etc.) and metadata about the selected secondarycopy, in order to determine whether this is the appropriate copy to berestored, e.g., date that the original primary data was created. Storagemanager 140 will then instruct media agent 144A and an appropriate dataagent 142 on the target client computing device 102 to restore secondarycopy 116A to primary storage device 104. A media agent may be selectedfor use in the restore operation based on a load balancing algorithm, anavailability based algorithm, or other criteria. The selected mediaagent, e.g., 144A, retrieves secondary copy 116A from disk library 108A.For instance, media agent 144A may access its index 153 to identify alocation of backup copy 116A on disk library 108A, or may accesslocation information residing on disk library 108A itself.

In some cases a backup copy 116A that was recently created or accessed,may be cached to speed up the restore operation. In such a case, mediaagent 144A accesses a cached version of backup copy 116A residing inindex 153, without having to access disk library 108A for some or all ofthe data. Once it has retrieved backup copy 116A, the media agent 144Acommunicates the data to the requesting client computing device 102.Upon receipt, file system data agent 142A and email data agent 142B mayunpack (e.g., restore from a backup format to the native applicationformat) the data in backup copy 116A and restore the unpackaged data toprimary storage device 104. In general, secondary copies 116 may berestored to the same volume or folder in primary storage device 104 fromwhich the secondary copy was derived; to another storage location orclient computing device 102; to shared storage, etc. In some cases, thedata may be restored so that it may be used by an application 110 of adifferent version/vintage from the application that created the originalprimary data 112.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512 MB, 1 GB, 2 GB, 4GB, or 8 GB chunks). This can facilitate efficient communication andwriting to secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to one or more secondary storage devices 108. Insome cases, users can select different chunk sizes, e.g., to improvethroughput to tape storage devices. Generally, each chunk can include aheader and a payload. The payload can include files (or other dataunits) or subsets thereof included in the chunk, whereas the chunkheader generally includes metadata relating to the chunk, some or all ofwhich may be derived from the payload. For example, during a secondarycopy operation, media agent 144, storage manager 140, or other componentmay divide files into chunks and generate headers for each chunk byprocessing the files. Headers can include a variety of information suchas file and/or volume identifier(s), offset(s), and/or other informationassociated with the payload data items, a chunk sequence number, etc.Importantly, in addition to being stored with secondary copy 116 onsecondary storage device 108, chunk headers can also be stored to index153 of the associated media agent(s) 144 and/or to index 150 associatedwith storage manager 140. This can be useful for providing fasterprocessing of secondary copies 116 during browsing, restores, or otheroperations. In some cases, once a chunk is successfully transferred to asecondary storage device 108, the secondary storage device 108 returnsan indication of receipt, e.g., to media agent 144 and/or storagemanager 140, which may update their respective indexes 153, 150accordingly. During restore, chunks may be processed (e.g., by mediaagent 144) according to the information in the chunk header toreassemble the files.

Data can also be communicated within system 100 in data channels thatconnect client computing devices 102 to secondary storage devices 108.These data channels can be referred to as “data streams,” and multipledata streams can be employed to parallelize an information managementoperation, improving data transfer rate, among other advantages. Somedata formatting techniques including techniques involving datastreaming, chunking, and the use of other data structures in creatingsecondary copies are described in U.S. Pat. Nos. 7,315,923, 8,156,086,and 8,578,120.

FIGS. 1F and 1G are diagrams of data streams 170 and 171, respectively,which may be employed for performing information management operations.Referring to FIG. 1F, data agent 142 forms data stream 170 from sourcedata associated with a client computing device 102 (e.g., primary data112). Data stream 170 is composed of multiple pairs of stream header 172and stream data (or stream payload) 174. Data streams 170 and 171 shownin the illustrated example are for a single-instanced storage operation,and a stream payload 174 therefore may include both single-instance (SI)data and/or non-SI data. A stream header 172 includes metadata about thestream payload 174. This metadata may include, for example, a length ofthe stream payload 174, an indication of whether the stream payload 174is encrypted, an indication of whether the stream payload 174 iscompressed, an archive file identifier (ID), an indication of whetherthe stream payload 174 is single instanceable, and an indication ofwhether the stream payload 174 is a start of a block of data.

Referring to FIG. 1G, data stream 171 has the stream header 172 andstream payload 174 aligned into multiple data blocks. In this example,the data blocks are of size 64 KB. The first two stream header 172 andstream payload 174 pairs comprise a first data block of size 64 KB. Thefirst stream header 172 indicates that the length of the succeedingstream payload 174 is 63 KB and that it is the start of a data block.The next stream header 172 indicates that the succeeding stream payload174 has a length of 1 KB and that it is not the start of a new datablock. Immediately following stream payload 174 is a pair comprising anidentifier header 176 and identifier data 178. The identifier header 176includes an indication that the succeeding identifier data 178 includesthe identifier for the immediately previous data block. The identifierdata 178 includes the identifier that the data agent 142 generated forthe data block. The data stream 171 also includes other stream header172 and stream payload 174 pairs, which may be for SI data and/or non-SIdata.

FIG. 1H is a diagram illustrating data structures 180 that may be usedto store blocks of SI data and non-SI data on a storage device (e.g.,secondary storage device 108). According to certain embodiments, datastructures 180 do not form part of a native file system of the storagedevice. Data structures 180 include one or more volume folders 182, oneor more chunk folders 184/185 within the volume folder 182, and multiplefiles within chunk folder 184. Each chunk folder 184/185 includes ametadata file 186/187, a metadata index file 188/189, one or morecontainer files 190/191/193, and a container index file 192/194.Metadata file 186/187 stores non-SI data blocks as well as links to SIdata blocks stored in container files. Metadata index file 188/189stores an index to the data in the metadata file 186/187. Containerfiles 190/191/193 store SI data blocks. Container index file 192/194stores an index to container files 190/191/193. Among other things,container index file 192/194 stores an indication of whether acorresponding block in a container file 190/191/193 is referred to by alink in a metadata file 186/187. For example, data block B2 in thecontainer file 190 is referred to by a link in metadata file 187 inchunk folder 185. Accordingly, the corresponding index entry incontainer index file 192 indicates that data block B2 in container file190 is referred to. As another example, data block B1 in container file191 is referred to by a link in metadata file 187, and so thecorresponding index entry in container index file 192 indicates thatthis data block is referred to.

As an example, data structures 180 illustrated in FIG. 1H may have beencreated as a result of separate secondary copy operations involving twoclient computing devices 102. For example, a first secondary copyoperation on a first client computing device 102 could result in thecreation of the first chunk folder 184, and a second secondary copyoperation on a second client computing device 102 could result in thecreation of the second chunk folder 185. Container files 190/191 in thefirst chunk folder 184 would contain the blocks of SI data of the firstclient computing device 102. If the two client computing devices 102have substantially similar data, the second secondary copy operation onthe data of the second client computing device 102 would result in mediaagent 144 storing primarily links to the data blocks of the first clientcomputing device 102 that are already stored in the container files190/191. Accordingly, while a first secondary copy operation may resultin storing nearly all of the data subject to the operation, subsequentsecondary storage operations involving similar data may result insubstantial data storage space savings, because links to already storeddata blocks can be stored instead of additional instances of datablocks.

If the operating system of the secondary storage computing device 106 onwhich media agent 144 operates supports sparse files, then when mediaagent 144 creates container files 190/191/193, it can create them assparse files. A sparse file is a type of file that may include emptyspace (e.g., a sparse file may have real data within it, such as at thebeginning of the file and/or at the end of the file, but may also haveempty space in it that is not storing actual data, such as a contiguousrange of bytes all having a value of zero). Having container files190/191/193 be sparse files allows media agent 144 to free up space incontainer files 190/191/193 when blocks of data in container files190/191/193 no longer need to be stored on the storage devices. In someexamples, media agent 144 creates a new container file 190/191/193 whena container file 190/191/193 either includes 100 blocks of data or whenthe size of the container file 190 exceeds 50 MB. In other examples,media agent 144 creates a new container file 190/191/193 when acontainer file 190/191/193 satisfies other criteria (e.g., it containsfrom approx. 100 to approx. 1000 blocks or when its size exceedsapproximately 50 MB to 1 GB). In some cases, a file on which a secondarycopy operation is performed may comprise a large number of data blocks.For example, a 100 MB file may comprise 400 data blocks of size 256 KB.If such a file is to be stored, its data blocks may span more than onecontainer file, or even more than one chunk folder. As another example,a database file of 20 GB may comprise over 40,000 data blocks of size512 KB. If such a database file is to be stored, its data blocks willlikely span multiple container files, multiple chunk folders, andpotentially multiple volume folders. Restoring such files may requireaccessing multiple container files, chunk folders, and/or volume foldersto obtain the requisite data blocks.

Using Backup Data for Replication and Disaster Recovery (“LiveSynchronization”)

There is an increased demand to off-load resource intensive informationmanagement tasks (e.g., data replication tasks) away from productiondevices (e.g., physical or virtual client computing devices) in order tomaximize production efficiency. At the same time, enterprises expectaccess to readily-available up-to-date recovery copies in the event offailure, with little or no production downtime.

FIG. 2A illustrates a system 200 configured to address these and otherissues by using backup or other secondary copy data to synchronize asource subsystem 201 (e.g., a production site) with a destinationsubsystem 203 (e.g., a failover site). Such a technique can be referredto as “live synchronization” and/or “live synchronization replication.”In the illustrated embodiment, the source client computing devices 202 ainclude one or more virtual machines (or “VMs”) executing on one or morecorresponding VM host computers 205 a, though the source need not bevirtualized. The destination site 203 may be at a location that isremote from the production site 201, or may be located in the same datacenter, without limitation. One or more of the production site 201 anddestination site 203 may reside at data centers at known geographiclocations, or alternatively may operate “in the cloud.”

The synchronization can be achieved by generally applying an ongoingstream of incremental backups from the source subsystem 201 to thedestination subsystem 203, such as according to what can be referred toas an “incremental forever” approach. FIG. 2A illustrates an embodimentof a data flow which may be orchestrated at the direction of one or morestorage managers (not shown). At step 1, the source data agent(s) 242 aand source media agent(s) 244 a work together to write backup or othersecondary copies of the primary data generated by the source clientcomputing devices 202 a into the source secondary storage device(s) 208a. At step 2, the backup/secondary copies are retrieved by the sourcemedia agent(s) 244 a from secondary storage. At step 3, source mediaagent(s) 244 a communicate the backup/secondary copies across a networkto the destination media agent(s) 244 b in destination subsystem 203.

As shown, the data can be copied from source to destination in anincremental fashion, such that only changed blocks are transmitted, andin some cases multiple incremental backups are consolidated at thesource so that only the most current changed blocks are transmitted toand applied at the destination. An example of live synchronization ofvirtual machines using the “incremental forever” approach is found inU.S. Patent Application No. 62/265,339 entitled “Live Synchronizationand Management of Virtual Machines across Computing and VirtualizationPlatforms and Using Live Synchronization to Support Disaster Recovery.”Moreover, a deduplicated copy can be employed to further reduce networktraffic from source to destination. For instance, the system can utilizethe deduplicated copy techniques described in U.S. Pat. No. 9,239,687,entitled “Systems and Methods for Retaining and Using Data BlockSignatures in Data Protection Operations.”

At step 4, destination media agent(s) 244 b write the receivedbackup/secondary copy data to the destination secondary storagedevice(s) 208 b. At step 5, the synchronization is completed when thedestination media agent(s) and destination data agent(s) 242 b restorethe backup/secondary copy data to the destination client computingdevice(s) 202 b. The destination client computing device(s) 202 b may bekept “warm” awaiting activation in case failure is detected at thesource. This synchronization/replication process can incorporate thetechniques described in U.S. patent application Ser. No. 14/721,971,entitled “Replication Using Deduplicated Secondary Copy Data.”

Where the incremental backups are applied on a frequent, on-going basis,the synchronized copies can be viewed as mirror or replication copies.Moreover, by applying the incremental backups to the destination site203 using backup or other secondary copy data, the production site 201is not burdened with the synchronization operations. Because thedestination site 203 can be maintained in a synchronized “warm” state,the downtime for switching over from the production site 201 to thedestination site 203 is substantially less than with a typical restorefrom secondary storage. Thus, the production site 201 may flexibly andefficiently fail over, with minimal downtime and with relativelyup-to-date data, to a destination site 203, such as a cloud-basedfailover site. The destination site 203 can later be reversesynchronized back to the production site 201, such as after repairs havebeen implemented or after the failure has passed.

Integrating with the Cloud Using File System Protocols

Given the ubiquity of cloud computing, it can be increasingly useful toprovide data protection and other information management services in ascalable, transparent, and highly plug-able fashion. FIG. 2B illustratesan information management system 200 having an architecture thatprovides such advantages, and incorporates use of a standard file systemprotocol between primary and secondary storage subsystems 217, 218. Asshown, the use of the network file system (NFS) protocol (or any anotherappropriate file system protocol such as that of the Common InternetFile System (CIFS)) allows data agent 242 to be moved from the primarystorage subsystem 217 to the secondary storage subsystem 218. Forinstance, as indicated by the dashed box 206 around data agent 242 andmedia agent 244, data agent 242 can co-reside with media agent 244 onthe same server (e.g., a secondary storage computing device such ascomponent 106), or in some other location in secondary storage subsystem218.

Where NFS is used, for example, secondary storage subsystem 218allocates an NFS network path to the client computing device 202 or toone or more target applications 210 running on client computing device202. During a backup or other secondary copy operation, the clientcomputing device 202 mounts the designated NFS path and writes data tothat NFS path. The NFS path may be obtained from NFS path data 215stored locally at the client computing device 202, and which may be acopy of or otherwise derived from NFS path data 219 stored in thesecondary storage subsystem 218.

Write requests issued by client computing device(s) 202 are received bydata agent 242 in secondary storage subsystem 218, which translates therequests and works in conjunction with media agent 244 to process andwrite data to a secondary storage device(s) 208, thereby creating abackup or other secondary copy. Storage manager 240 can include apseudo-client manager 217, which coordinates the process by, among otherthings, communicating information relating to client computing device202 and application 210 (e.g., application type, client computing deviceidentifier, etc.) to data agent 242, obtaining appropriate NFS path datafrom the data agent 242 (e.g., NFS path information), and deliveringsuch data to client computing device 202.

Conversely, during a restore or recovery operation client computingdevice 202 reads from the designated NFS network path, and the readrequest is translated by data agent 242. The data agent 242 then workswith media agent 244 to retrieve, re-process (e.g., re-hydrate,decompress, decrypt), and forward the requested data to client computingdevice 202 using NFS.

By moving specialized software associated with system 200 such as dataagent 242 off the client computing devices 202, the architectureeffectively decouples the client computing devices 202 from theinstalled components of system 200, improving both scalability andplug-ability of system 200. Indeed, the secondary storage subsystem 218in such environments can be treated simply as a read/write NFS targetfor primary storage subsystem 217, without the need for informationmanagement software to be installed on client computing devices 202. Asone example, an enterprise implementing a cloud production computingenvironment can add VM client computing devices 202 without installingand configuring specialized information management software on theseVMs. Rather, backups and restores are achieved transparently, where thenew VMs simply write to and read from the designated NFS path. Anexample of integrating with the cloud using file system protocols orso-called “infinite backup” using NFS share is found in U.S. PatentApplication No. 62/294,920, entitled “Data Protection Operations Basedon Network Path Information.” Examples of improved data restorationscenarios based on network-path information, including using storedbackups effectively as primary data sources, may be found in U.S. PatentApplication No. 62/297,057, entitled “Data Restoration Operations Basedon Network Path Information.”

Highly Scalable Managed Data Pool Architecture

Enterprises are seeing explosive data growth in recent years, often fromvarious applications running in geographically distributed locations.FIG. 2C shows a block diagram of an example of a highly scalable,managed data pool architecture useful in accommodating such data growth.The illustrated system 200, which may be referred to as a “web-scale”architecture according to certain embodiments, can be readilyincorporated into both open compute/storage and common-cloudarchitectures.

The illustrated system 200 includes a grid 245 of media agents 244logically organized into a control tier 231 and a secondary or storagetier 233. Media agents assigned to the storage tier 233 can beconfigured to manage a secondary storage pool 208 as a deduplicationstore, and be configured to receive client write and read requests fromthe primary storage subsystem 217, and direct those requests to thesecondary tier 233 for servicing. For instance, media agents CMA1-CMA3in the control tier 231 maintain and consult one or more deduplicationdatabases 247, which can include deduplication information (e.g., datablock hashes, data block links, file containers for deduplicated files,etc.) sufficient to read deduplicated files from secondary storage pool208 and write deduplicated files to secondary storage pool 208. Forinstance, system 200 can incorporate any of the deduplication systemsand methods shown and described in U.S. Pat. No. 9,020,900, entitled“Distributed Deduplicated Storage System,” and U.S. Pat. Pub. No.2014/0201170, entitled “High Availability Distributed DeduplicatedStorage System.”

Media agents SMA1-SMA6 assigned to the secondary tier 233 receive writeand read requests from media agents CMA1-CMA3 in control tier 231, andaccess secondary storage pool 208 to service those requests. Mediaagents CMA1-CMA3 in control tier 231 can also communicate with secondarystorage pool 208, and may execute read and write requests themselves(e.g., in response to requests from other control media agentsCMA1-CMA3) in addition to issuing requests to media agents in secondarytier 233. Moreover, while shown as separate from the secondary storagepool 208, deduplication database(s) 247 can in some cases reside instorage devices in secondary storage pool 208.

As shown, each of the media agents 244 (e.g., CMA1-CMA3, SMA1-SMA6,etc.) in grid 245 can be allocated a corresponding dedicated partition251A-251I, respectively, in secondary storage pool 208. Each partition251 can include a first portion 253 containing data associated with(e.g., stored by) media agent 244 corresponding to the respectivepartition 251. System 200 can also implement a desired level ofreplication, thereby providing redundancy in the event of a failure of amedia agent 244 in grid 245. Along these lines, each partition 251 canfurther include a second portion 255 storing one or more replicationcopies of the data associated with one or more other media agents 244 inthe grid.

System 200 can also be configured to allow for seamless addition ofmedia agents 244 to grid 245 via automatic configuration. As oneexample, a storage manager (not shown) or other appropriate componentmay determine that it is appropriate to add an additional node tocontrol tier 231, and perform some or all of the following: (i) assessthe capabilities of a newly added or otherwise available computingdevice as satisfying a minimum criteria to be configured as or hosting amedia agent in control tier 231; (ii) confirm that a sufficient amountof the appropriate type of storage exists to support an additional nodein control tier 231 (e.g., enough disk drive capacity exists in storagepool 208 to support an additional deduplication database 247); (iii)install appropriate media agent software on the computing device andconfigure the computing device according to a pre-determined template;(iv) establish a partition 251 in the storage pool 208 dedicated to thenewly established media agent 244; and (v) build any appropriate datastructures (e.g., an instance of deduplication database 247). An exampleof highly scalable managed data pool architecture or so-called web-scalearchitecture for storage and data management is found in U.S. PatentApplication No. 62/273,286 entitled “Redundant and Robust DistributedDeduplication Data Storage System.”

The embodiments and components thereof disclosed in FIGS. 2A, 2B, and2C, as well as those in FIGS. 1A-1H, may be implemented in anycombination and permutation to satisfy data storage management andinformation management needs at one or more locations and/or datacenters.

Block-Level Data Replication

Some implementations of data replication may be performed at thefile-system level such that changes to the file system are monitored andreplicated onto a destination device. However, it may be difficult toapply such data replication techniques to systems that do not have afile system. Additionally, if live data is replicated directly onto thedestination device in real time, data errors and abnormalities thatoccur on the source device may also be replicated onto the destinationdevice, rendering the replicated data unusable. Further, the cache usedfor tracking the changes to the source device is typically small, so ifthe source device experiences a high volume of I/O operations or reducednetwork resources, the changes stored in the cache may not be able to bewritten to the destination device fast enough, and the cache may becomefull, causing the data replication to fail. Therefore, an improvedmethod of performing block-level replication is desired.

Certain embodiments described herein relate to an improved informationmanagement system for performing block-level replication. In someembodiments, one or more components in the information management systemcan perform block-level replication with or without using a recoverypoint store configured to store historical replication data depending onthe needs of the user. Additionally, using hydration and dehydrationtechniques, the system can continue performing block-level replicationeven when the system is having storage capacity and/or network issues.Further, dynamically merging recovery points in the recovery point storefor data replication can reduce storage resource consumption. These andother embodiments are described in greater detail below with referenceto the drawings below.

FIG. 3 is a block diagram illustrating a data storage management system300 (also referred to herein as system 300) configured to implement ablock-level data replication process in accordance with one or moreembodiments disclosed herein. As illustrated, the system 300 includes aclient computing device 302, a storage manager 304, a secondary storagecomputing device 306, a secondary storage device 308, and a destinationdevice 310. The client computing device 302 and the destination device310 may sometimes be referred to as a primary storage subsystem 300A,and some or all of the storage manager 304, the secondary storagecomputing device 306, and the secondary storage device 308 may sometimesbe referred to as a secondary storage subsystem 300B. In someembodiments, the storage manager 304 may be part of the primary storagesubsystem 300A instead of the secondary storage subsystem 300B, or maybe part of neither the primary storage subsystem 300A nor the secondarystorage subsystem 300B. In some embodiments, the destination device 310may be part of the secondary storage subsystem 300B instead of theprimary storage subsystem 300A.

The client computing device 302 may include one or more hardwareprocessors and corresponding computer memory. For example, the clientcomputing device 302 may be any computing device capable of processingdata such as, for example, a server computer, a workstation, a personalcomputer, a cell phone, a portable computing device, a tablet computer,a handheld computing device, a personal digital assistant (PDA) or thelike.

The client computing device 302 includes an application 312 that may beresiding on and/or being executed by the client computing device 302.The application 312 may be a software application that interacts with auser to process data and may be, for example, a database application(e.g., SQL), a word processing application, a spreadsheet application, afinancial application, a management application, an e-commerceapplication, a browser, or a combination thereof, and/or any otherapplication described herein. Although the example of FIG. 3 shows onlya single application, any number of applications may be installed or maybe executing on the client computing device 302.

The illustrated client computing device 302 further includes a filesystem 314 for organizing files and directories accessible by the clientcomputing device 302. In some embodiments, the file system 314 comprisesa data structure usable to keep track of a collection of files and/ordirectories stored on the source storage device 318. The file system 314may include, for example, a local file system, a network file system, afile server, a management program or the like, or may include multiplefile systems accessible by an operating system. For instance, inembodiments wherein the source storage device 318 is associated withmultiple volumes, each volume may be associated with its own file system314, or a single file system 314 may span across the multiple volumes.

The illustrated client computing device 302 further includes ablock-level filter driver 316 that interacts with data (e.g., productiondata) associated with the client computing device 302. For example, theblock-level filter driver 316 may be a volume filter driver, a filesystem filter driver, an operating system driver, a filtering program, adata trapping program, an application, a module of the application 312,an application programming interface (“API”), or other like softwaremodule or process that, among other things, monitors and/or interceptsparticular requests targeted at a disk volume, a file system, networkattached storage (“NAS”), a storage area network (“SAN”), mass storageand/or other memory or raw data. In some embodiments, the block-levelfilter driver 316 may reside in the I/O stack and may intercept, analyzeand/or copy certain data traveling to a disk volume, a file system, or aNAS device.

The block-level filter driver 316 may intercept data modificationoperations (e.g., data writes) that changes one or more blocks stored inthe disk volume or file system. For example, the block-level filterdriver 316 may locate, monitor, and/or process one or more of thefollowing with respect to one or more applications running on the clientcomputing device 302: data management operations (e.g., data writeoperations, file attribute modifications), logs or journals (e.g., NTFSchange journal), configuration files, file settings, control files,combinations of the same or the like.

In some embodiments, multiple filter drivers 316 may be deployed on theclient computing device 302, each filter driver being dedicated to, forexample, data of a particular application, a particular file system, ora particular disk volume. In such embodiments, not all informationassociated with the client computing device 302 may be captured by anyone of such filter drivers 316 and, thus, the impact on systemperformance may be reduced. In other embodiments, the block-level filterdriver 316 may be suitable for use with multiple applications, filesystems, or disk volumes and/or may be adaptable or configurable for usewith multiple applications, file systems, and/or disk volumes. Forexample, one or more instances of customized or particularizingfiltering programs may be instantiated based on application specifics orother needs or preferences.

The illustrated client computing device 302 further includes a sourcestorage device 318. The source storage device 318 may include any typeof media capable of storing data. For example, the source storage device318 may comprise flash storage, a disk drive, a hard-disk storage array,solid state memory, or any other type of storage. In some embodiments,the source storage device 318 includes one or more storage devicesinternal to the client computing device 302. Alternatively oradditionally, the source storage device 318 may include one or morestorage devices external to (e.g., remote to) the client computingdevice 302.

The illustrated client computing device 302 further includes a sourcereplication agent 320. The source replication agent 320 may manageand/or coordinate the compilation of and/or transfer of replication datafrom the client computing device 302 (e.g., to the destination device310). The source replication agent 320 may include one or more modulesand/or threads configured to perform one or more replication techniquesdescribed herein. In some embodiments, the source replication agent 320may also perform other data protection tasks such as backing up,archiving, migrating, and/or recovering data associated with the clientcomputing device 302. In other embodiments, the client computing device302 includes one or more data agents (e.g., similar to those describedherein with reference to FIGS. 1A-1H and 2A-2C) separate from the sourcereplication agent 320, and such data agents may be configured to performsuch data protection operations instead.

As further illustrated in FIG. 3 , the destination device 310 comprisesa destination replication agent 322 and a destination storage device324. In certain embodiments, the destination replication agent 322 isconfigured to monitor and/or manage the copying of data from the clientcomputing device 302 to the destination device 310, such as dataretrieved by the block-level filter driver 316 and/or data retrievedfrom the recovery point store 336. In other embodiments, the destinationreplication agent 322 is a “dumb” server or terminal that receives andexecutes instructions from the client computing device 302.

The destination storage device 324 may include any type of media capableof storing data, such as replication data sent from the client computingdevice 302. For example, the destination storage device 324 may compriseflash storage, a disk drive, a hard-disk storage array, solid statememory, or any other type of storage. In certain embodiments, thedestination storage device 324 may be internal and/or external to thecomputing device(s) having the destination replication agent 322.

In certain embodiments, the source storage device 318 and/or thedestination storage device 324 may be implemented as one or more storage“volumes” that include physical storage disks defining an overalllogical arrangement of storage space. For instance, disks within aparticular volume may be organized as one or more groups of redundantarray of independent (or inexpensive) disks (RAID). In certainembodiments, either or both of the storage devices 318 and 324 mayinclude multiple storage devices of the same or different media.

In certain embodiments, the source replication agent 320 and/or thedestination replication agent 322 may perform an initial “seeding” orsynchronization process as part of the block-level replication processdescribed herein. For example, prior to (or concurrently with) datareplication using the block-level filter driver 316, the sourcereplication agent 320 may perform a scan of the client computing device302 (e.g., the source storage device 318). For instance, the sourcereplication agent 320 may evaluate the folders and/or directorystructure of the client computing device 302 to determine which foldersare used by the application 312. In certain embodiments, the sourcereplication agent 320 may also identify, arrange, and queue necessarydata of the application 312 to provide a proper platform forreplication. For example, the source replication agent 320 may populatejournal queue(s) with application data that has already been written tothe source storage device 318. In certain embodiments, this initialsynchronization process is performed using a snapshot or point-in-timecopy of the file system 314 and/or the source volumes in the sourcestorage device 318. In other embodiments, the source replication agent320 scans live file system(s) and/or source volume(s).

In certain embodiments, the source replication agent 320 may accessand/or monitor particular data blocks, files, folders, directories,registries, preferences and/or other like data structures forinformation to be replicated. All or a portion of the informationgathered by the source replication agent 320 may be copied over to thedestination device 310 as part of the initial seeding or initializationprocess. After the seeding process is completed, block-level datareplication may occur on a substantially continuous basis based on thechanges made to the data stored in the source storage device 318.

As illustrated in FIG. 3 , the block-level filter driver 316 isadvantageously located between (i) the application 312 and/or the filesystem 314 and (ii) the source storage device 318. In some embodiments,the client computing device 302 does not have a file system. Forinstance, the block-level filter driver 316 may be deployed in the stackas an I/O buffer and/or process in the data path between the application312 or the file system 314 and the source storage device 318. In suchembodiments, the block-level filter driver 316 may intercept, snoop,supervise, trap, process or otherwise be cognizant of some or allblock-level and/or file-level operations (e.g., data modificationoperations, file modification operations, write operations, readoperations, and the like) from the application 312 or the file system314 to its associated location(s) on the source storage device 318.

The block-level filter driver 316 may further process and/or traversethe data and copy, generate, or examine other relevant information, suchas a journal queue entry number, time information (e.g., time stamp),application type, data size and start field, combinations of the same orthe like, that may be useful in the replication process. In otherembodiments, the block-level filter driver 316 monitors files on thesource storage device 318 for modifications of data relating to theapplication 312. For instance, the block-level filter driver 316 maymonitor a select group of data blocks, files, folders, and/or volumesthat are part of the source storage device 318. In certain embodiments,the block-level filter driver 316 or other system component may detectwhen a data write operation of the application 312 is made to a datablock, file, folder, or volume not in the select group. The block-levelfilter driver 316 or other system component may then refrain from addingan entry to the journal queue in response to the data write operation.Alternatively or additionally, block-level filter driver 316 or othersystem component may determine based on the properties of the data writeoperation whether or not the subject data block, file, folder, and/orvolume should be added to the select group (for subsequent monitoring).

In certain embodiments, the client computing device 302 communicateswith the destination device 310 to verify that the two systems aresynchronized. For instance, the client computing device 302 may receivefrom the destination device 310 an identifier (e.g., unique serialnumber) or an indicator (e.g., hash value) associate of the writeoperation currently being replicated (recently replicated) by thedestination device 310. The client computing device 302 may then comparethe received identifier or indicator with a corresponding identifier orindicator associated with the write operation being written (or recentlywritten) to the source storage device 318 and/or to the recovery pointstore 336.

The storage manger 304 may manage and store various preferences, rules,and policies regarding storage, backup, encryption, compression,replication, archival, or deduplication of the data (e.g., applicationdata generated by one or more applications running the client computingdevices) stored in the primary storage subsystem 300A. A systemadministrator may create, modify, and/or delete one or more storagepolicies via the storage manager 304. The storage manager 304 mayinitiate one or more data backup, replication, or archiving operationsbased on one or more thresholds specified by such storage policies. Insome embodiments, the storage manager 304 may perform one or moreoperations described herein as being performed by the source replicationagent 320 or the destination replication agent 322 instead of suchagent(s). In some embodiments, the storage manager 304 manages,coordinates, and/or facilitate the transmission of data between theclient computing device 302 and the destination device 310 forblock-level replication. In other embodiments, the block-levelreplication operations do not involve the storage manager 304. Thestorage manager 304 (or one or more components thereof) may be identicalor similar to the storage manager 140 (or one or more componentsthereof) described above with reference FIGS. 1A-1H and 2A-2C. Forexample, the storage manager 304 may further provide one or morefunctionalities of the storage manager 140 described above.

The secondary storage computing device 306 comprises one or morehardware processors and corresponding computer memory and includes amedia agent 332, media agent index data 334, and a recovery point store336.

The media agent 332 is a component of the system 300 and is analogous tomedia agent 144 described elsewhere herein. The media agent 332 canmanage, coordinate, and facilitate the transmission of data, as directedby the storage manager 304, to and/or from the secondary storage device308. The media agent 332 can also communicate with other storagemanagement components, such as data agents 142 (not shown), contentindexing servers (not shown), data analytics servers (not shown),reporting servers (not shown), and/or consoles for user access (notshown). In some embodiments, the media agent 332 manages, coordinates,and/or facilitate the transmission of data between the client computingdevice 302 and the destination device 310 for block-level replication.In other embodiments, the block-level replication operations do notinvolve the media agent 332.

The media agent 332 may be implemented as software that is hosted by thesecondary storage computing device 306. In some embodiments, thecombination of the media agent 332 and its underlying host secondarystorage computing device 306 may be referred to as a “media agent.” Inother embodiments, the underlying host secondary storage computingdevice 306 is said to perform the operations executed by media agent332.

In some embodiments, the media agent 332 may maintain an associatedmedia agent database, which may be stored to a disk or other storagedevice (not shown) that is local to the secondary storage computingdevice 306 on which the media agent 332 executes. In other cases, such amedia agent database may be stored separately from the host secondarystorage computing device 306. The media agent database can include,among other things, a media agent index data 334 (e.g., similar to mediaagent index 153 of FIG. 1C). In some cases, the media agent index data334 does not form a part of and is instead separate from the media agentdatabase.

The media agent index data 334 may be a data structure associated withthe particular media agent 306 that includes information about thestored data associated with the particular media agent and which may begenerated in the course of performing a secondary copy operation or arestore. The media agent index data 334 may provide a fast and efficientmechanism for locating/browsing secondary copies or other data stored inthe secondary storage devices 308 without having to access the secondarystorage device 308 to retrieve the information from there. For instance,for each secondary copy stored in the secondary storage device 308, themedia agent index data 334 may include metadata such as a list of thedata objects (e.g., files/subdirectories, database objects, mailboxobjects, etc.), a logical path to the secondary copy on thecorresponding secondary storage device 308, location information (e.g.,offsets) indicating where the data objects are stored in the secondarystorage device 308, when the data objects were created or modified, etc.Thus, the media agent index data 334 includes metadata associated withthe secondary copies that is readily available for use from the mediaagent 332. In some embodiments, some or all of the information in themedia agent index data 334 may instead or additionally be stored alongwith the secondary copies in the secondary storage device 308.

The information stored in the media agent index data 334 typicallycomprises data that reflects certain particulars about relatively recentsecondary copy operations. After some triggering event, such as after athreshold amount of time elapses or the media agent index data 334reaches a threshold size, certain portions of the media agent index data334 may be copied or migrated to the secondary storage device 308, e.g.,on a least-recently-used basis. This information may be retrieved anduploaded back into the media agent index data 334 or otherwise restoredto the media agent 332 to facilitate retrieval of data from thesecondary storage device 308. In some embodiments, the cachedinformation may include format or containerization information relatedto archives or other files stored on the secondary storage device 308.The media agent 332 may update the media agent index data 334 upon everybackup operation or other data protection operation.

The illustrated secondary storage computing device 306 further includesthe recovery point store 336. The recovery point store 336 essentiallykeeps track of a history of data replication between thesource-destination pair (e.g., source storage device 318 and destinationstorage device 324). In certain types of replication described herein(e.g., granular replication mode), change data (e.g., changes made todata blocks stored in the source storage device 318) detected on theclient computing device 302 is not directly written to the destinationdevice 310, but instead first written to the recovery point store 336and later transferred to the destination device 310. The change data isstored in the recovery point store 336 in the form of recovery points.As used herein, the phrase “recovery point” may refer to, in addition toits ordinary meaning, a collection of metadata and data associated withwrite operations that occurred during a specific period of time (e.g.,recovery point interval). For example, a recovery point stored in therecovery point store 336 may include all the data writes performed on asource volume that is part of the source storage device 318 between 1:00PM and 1:05 PM, Jul. 4, 2019, and such a recovery point can be used toupdate the destination storage device 324 (or the source storage device318) to the state of the source volume at 1:05 PM on Jul. 4, 2019, whenthe need arises (e.g., as part of replicating data to the destinationdevice 310 or for disaster recovery). The recovery point store 336 isdescribed in greater detail below with reference to FIGS. 4-8 .

The secondary storage device 308 is a storage device for mass datastorage, and any storage medium, e.g., flash, disk, tape, etc., can beused by the secondary storage device 308. The secondary storage device308 is referred to as a “secondary storage device,” because according tosome embodiments, it stores backup copies of data, e.g., secondary ortertiary copies and does not store primary or “live” data that isactively in use by the client computing devices 302. For example, backupcopies generated by the client computing devices 302 can be stored inthe secondary storage device 308. There is no limit on how manysecondary storage devices 308 are operating and/or in communication withthe media agent 332 and/or with other media agents in the system 300.The secondary storage device 308 may communicate with components otherthan those illustrated in FIG. 3 and store data other than thosedescribed herein.

The secondary storage device 308 may store any number of secondarycopies, such as backup copies of data stored on the client computingdevices 302 and/or backup copies generated by the client computingdevices 302. Although the secondary storage device 308 is shown as asingle secondary storage device in the example of FIG. 3 , it should beappreciated that any number of secondary storage devices may be used toimplement the secondary storage device 308, as described with referenceto FIG. 1D. For example, upon receiving a data backup request from theclient computing devices 302 or the storage manager 304, the media agent332 may route and/or store the data to the appropriate secondary storagedevice 308, or modify or add to the existing copy of the data stored inthe secondary storage device 308.

The secondary storage device 308 (or one or more components thereof) maybe identical or similar to the secondary storage device 108 (or one ormore components thereof) described above with reference FIGS. 1A-1H and2A-2C. For example, the secondary storage device 308 may further provideone or more functionalities of the secondary storage device 108described above.

The system 300 and corresponding components of FIG. 3 may be identicalor similar to the systems 100 or 200 (and similarly named componentsshown in any of FIGS. 1A-1H and 2A-2C, where applicable, such as FIG.1D). All components of the system 300 can be in direct communicationwith each other or communicate indirectly via the client computingdevice 302, the destination device 310, the storage manager 304, thesecondary storage computing device 306, the secondary storage device308, or the like. In certain embodiments, some of the components in FIG.3 shown as separate components can reside on a single computing device.Alternatively, or additionally, one or more components shown in FIG. 3as residing on a single computing device can be distributed acrossmultiple devices.

The depicted components are logically interconnected as shown by thearrows. The physical communications infrastructure required to supportthese logical connections can be implemented by any suitable electroniccommunications infrastructure, such as that described in regard tocommunication pathways 114 above. There is no limitation on how many ofthe depicted kinds of components can be configured in a givenimplementation of system 300 (e.g., client computing devices 302,destination devices 310, media agents 332, secondary storage devices308).

FIG. 4 is a flow diagram illustrating one embodiment of a method 400 forperforming block-level data replication using a recovery point store.The method 400 is described with respect to the system 300 of FIG. 3 .However, one or more of the steps of the method 400 may be implementedby other information management systems, such as those described ingreater detail above with reference to FIG. 1D. The method 400 can beimplemented by any one of, or a combination of, of a client computingdevice, a destination device, a storage manager, a data agent, a mediaagent, and the like. Although the steps in the method 400 are describedas being performed by the destination replication agent 322 destinationreplication agent 322 of the system 300, the embodiments discussedherein are not limited as such, and one or more of the steps in themethod 400 may be performed by other components of the system 300 (e.g.,the source replication agent 320, the storage manager 304, and/or themedia agent 332), either alone or in combination.

At block 402, the destination replication agent 322 receives a requestto perform a first block-level replication between a source storagedevice (e.g., source storage device 318) and a destination storagedevice (e.g., destination storage device 324). The source storage devicemay store primary data generated by one or more applications installedon a client computing device (e.g., client computing device 302), wherethe primary data comprises a plurality of data blocks. Thesource-destination pair for which the block-level replication is to beperformed may be recorded in a source-destination pair database, wherethe database includes details about the source storage device,destination storage device, source type, destination type, recoverypoint store identifier, source volume (e.g., the storage volume on thesource storage device to be replicated), destination mount path (e.g.,the path on the destination storage device in which the replicated datawill be written), and the like. The source-destination pair may includejust a single source volume to be replicated. Alternatively, thesource-destination pair may include multiple source volumes to bereplicated, and each source volume may be associated with a differentdestination mount path. The list of source volumes for a givensource-destination pair may be stored in the same database as thesource-destination pair database, or in a separate database. Theparameters defining the replication described herein (e.g., replicationinterval, retention period, etc.) may be user-specified, determined by acomponent of the system 300 (e.g., source replication agent 320,destination replication agent 322, and/or storage manager 304), or acombination thereof.

In some embodiments, the system (e.g., source replication agent 320,destination replication agent 322, and/or storage manager 304) maydetermine whether the source volume is an operating system volume (e.g.,a volume on which the operating system is installed), and if so, refrainfrom performing block-level data replication on the source volume (ordisable block-level data replication on the source volume). In otherembodiments, the system may determine whether the source volume is adata volume (e.g., a volume on which the operating system is notinstalled), and if so, perform block-level data replication on thesource volume (or allow block-level data replication on the sourcevolume). In yet other embodiments, the system performs block-level datareplication regardless of whether the source volume is an operatingsystem volume or not.

At block 404, the destination replication agent 322 performs an initialsynchronization between the source storage device and the destinationstorage device, wherein the initial synchronization comprises comparingsource data stored in the source storage device to destination datastored in the destination storage device, and updating the destinationdata such that the destination data is identical to the source data. Forexample, the destination replication agent 322 may compare the hashvalues of the source and destination data blocks (e.g., using SHA-256),and whenever the hash values are different, cause the source data blockto be copied onto the destination storage device 324. In someembodiments, the destination replication agent 322 compares all datablocks in the source volume. In other embodiments, the destinationreplication agent 322 compares only data blocks determined to be valid(e.g., containing valid data and/or allocated by the file system). Afterblock 404, the source replication agent 320 (e.g., via the block-levelfilter driver 316) may begin monitoring the block-level changes thatoccur to the source storage device 318 (or to one or more specificsource storage volumes therein).

At block 406, the destination replication agent 322 receives anindication that a change was made to a first block stored in the sourcestorage device, wherein the change is associated with a write operationperformed on the client computing device. An example of a process forrecording and communicating block-level changes to the destinationreplication agent 322 is illustrated in FIG. 5 .

FIG. 5 illustrates a block diagram of an exemplary embodiment of ajournal entry creation data path 500 usable to generate journal entries.As shown, the data path 500 includes the block-level filter driver 316that monitors data management operations, such as data write operationsor file attribute modification operations. For instance, such operationsmay comprise changes to data in a production level memory. Examples ofembodiments of filter drivers usable with the data path 500 aredescribed in more detail herein.

The block-level filter driver 316 can populate a queue 504 with journalentries (or journal entries), related to detected data modificationoperations that would modify one or more data blocks in the sourcestorage device. The queue 504 may store the journal entries until theyare processed by a driver thread (or process) 506. In some embodiments,the queue 504 is implemented in volatile memory on the client computingdevice 302.

The queue 504 forwards the journal entries to the driver thread 506. Insome embodiments, the driver thread 506 polls the queue 504 for journalentries that are newly generated by the block-level filter driver 316.The driver thread 506 subsequently stores the journal entries in abuffer 508. The buffer 508 may be a memory-based queue for storing thejournal entries until the journal entries are processed by a replicationthread (or process) 512. The replication thread 512 may send the journalentry to a desired destination, such as the destination device 310, forfurther processing.

As shown in FIG. 5 , the buffer 508 may store excess journal entries inmemory 510. In certain embodiments, the memory 510 may comprise a diskand/or may be located on the storage device of the client computingdevice 302. In some embodiments, one or more operations described hereinas being performed by the one or more components shown in FIG. 5 mayinstead be performed by the source replication agent 320.

With continued reference to FIG. 4 , at block 408, the destinationreplication agent 322 determines whether the first block-levelreplication is to be performed in a granular replication mode, areplication mode in which changed data is first stored in a recoverypoint store prior to being stored in the destination storage device, andthe recovery point store is configured to store at least some historicaldata not stored in the destination storage device. In some cases, therequested replication may be performed in a live synchronization mode inwhich changed data is stored directly in the destination storage devicewithout first being stored in a recovery point store. In such a mode,the recovery point store may not be utilized for the replication (e.g.,to store historical data associated with the source storage device). Anexample of an entry stored in the recovery point store is illustrated inFIG. 6 .

FIG. 6 illustrates an exemplary embodiment of a data structure of arecovery point store entry 600 usable with the replication systemsdescribed herein. In certain embodiments, the recovery point store entry600 comprises information regarding prior states of the sourcedestination device 318 (e.g., “recovery points” to which the sourcestorage device can be restored). As shown in FIG. 6 , the recovery pointstore entry 600 includes a recovery point identifier 602, a sourceidentifier 604, a destination identifier 606, a source location 608, adestination location 610, a timestamp 612, an interval 614, anapplication consistent recover point (ACRP) flag 616, a sequence number618, and payload data 620. In some embodiments, a recovery point storeentry may include only a subset of the fields shown in FIG. 6 , and/orinclude one or more additional fields not shown in FIG. 6 .

The recovery point ID 602, the source ID 604, and the destination ID 606may be identifiers that uniquely identify the recovery point, sourcestorage device (or volume), and destination storage device (or volume)associated with the recovery point store entry 600, respectively. Thesource location 608 and the destination location 610 may indicate thelocations of the replicated data within the respective source anddestination storage devices. The timestamp 612 may be the timeassociated with the recovery point (e.g., the point in time when thesource storage device exhibited the state of data reflected by therecovery point).

The interval 614 may indicate the period of time encompassed by therecovery point (e.g., the temporal gap between the recovery pointassociated with the recovery point store entry 600 and the recoverypoint that immediately precedes the recovery point associated with therecovery point store entry 600 in the recovery point store). In someembodiments, the recovery point stored in the recovery point storeincludes all changes that occurred on the source storage device duringthe interval (e.g., metadata and data corresponding to every writeoperation during the interval). In other embodiments, the recovery pointincludes only data corresponding to the final state represented by therecovery point (e.g., what the source storage device looks like at theend of the interval as a result of all the write operations thatoccurred during the interval).

The ACRP flag 616 indicates whether the recovery point associated withthe recovery point store entry 600 is an application consistent recoverypoint or not (e.g., crash consistent recovery point). The block-leveldata replication described herein may be performed using crashconsistent recovery points (CCRPs) as well as application consistentrecovery points (ACRPs). Unlike CCRPs, ACRPs may involve creating asnapshot of the source storage device and/or flushing the applicationbuffers to the source storage device prior to generation. For example,creating an ACRP may involve (i) creating a snapshot volume, (ii)flushing the application buffer data to the snapshot volume, (iii)recording the changes happening to the snapshot volume in the journalqueue and recording the changes happening to the live source volume in atemporary journal queue, (iv) flushing the journal queue to the recoverypoint store, (v) flushing the temporary journal queue to the recoverypoint store, and (vi) resuming replication to the recovery point store.In some cases, ACRPs are not generated as frequently as CCRPs (e.g., dueto the more demanding nature of ACRPs). Although not shown in FIG. 6 ,the entries in the recovery point store may indicate how long therecovery points are to be retained in the recovery point store (e.g.,“retention period” after which a recovery point is to be removed fromthe recovery point store and/or written to the destination storagedevice). In some cases, the retention period is longer than the intervalat which CCRPs and/or ACRPs are generated. For example, the user mayhave configured the block-level data replication such that CCRPs aregenerated every 5 minutes, ACRPs are generated every 2 hours, and theretention period is 2 days.

The sequence number 618 may indicate the sequence number associated withthe recovery point. For example, the sequence number may be a 64-bitunsigned integer that is assigned to every write operation that occurson the source storage device. For example, the sequence number mayindicate the most recent write operation associated with the recoverypoint. As another example, the sequence number may be range of numbersindicating the collection of write operations associated with therecovery point. The payload data 620 may be the actual write data thatis associated with the recovery point (e.g., data written to the sourcestorage device by the one or more write operations associated with therecovery point).

With continued reference to FIG. 4 , at block 410, the destinationreplication agent 322, based on determining that the first block-levelreplication is to be performed in the granular replication mode, causesthe change to the first block to be recorded in a first recovery pointstore (e.g., recovery point store 336), wherein the first recovery pointstore is configured to store a plurality of recovery points associatedwith the source storage device. In some embodiments, the destinationreplication agent 322 monitors the block-level changes, determineswhether the condition for recording the changes in a new recovery pointhas been satisfied (e.g., every two hours), and based on determiningthat the condition for creating a new recovery point has been satisfied,records the changes accumulated since the last recovery point in a newrecovery point in the recovery point store. In other embodiments, theblock-level changes are transmitted from the client computing device 302to the recovery point store 336 regardless of whether the condition forcreating a new recovery point has been satisfied, and the changes areperiodically (e.g., at every CCRP and/or ACRP interval) recovery pointinterval packaged into a new recovery point.

At block 412, the destination replication agent 322 determines whether acondition for writing the changes to the destination storage deviceusing one of the plurality of recovery points stored in the firstrecovery point store is satisfied. Based on determining that thecondition for writing the changes to the destination storage device issatisfied, the method 400 proceeds to block 414. Otherwise, the methodproceeds to block 406 to continue detecting and recording theblock-level changes to the recovery point store.

At block 414, the destination replication agent 322, based ondetermining that the condition for writing the changes to thedestination storage device is satisfied, causes the changes detected atblock 406 to be written to the destination device 310. In the granularreplication mode, the changes may have been first recorded in therecovery point store, and upon the condition for writing the changes tothe destination storage device being satisfied, written to thedestination device 310. For example, upon expiration of a given recoverypoint stored in the recovery point store 336, the destinationreplication agent 322 may retrieve the recovery point and write the dataassociated with the recovery point to the destination storage device324. In another example, after every retention period, the destinationreplication agent 322 may retrieve one of the recovery points from therecovery point store and write the data associated with the recoverypoint to the destination storage device 324. The recovery point selectedby the destination replication agent 322 may be the oldest recoverypoint, the most recent recovery point, or the recovery point that isapproximately as old as the retention period (e.g., recovery point thatis closest to being 2 days old if the retention period is 2 days).

After the changes are written to the destination device 310, the datastored in the destination storage device 324 can be used to recover orrestore data. In some embodiments, the destination replication agent322, upon user request, can cause data stored in the destination storagedevice 324 or the recovery point store 336 to be written back onto thesource storage device 318. Alternatively or additionally, thedestination replication agent 322 can cause the destination storagedevice 324 to be directly accessible by the application(s) running onthe client computing device 302 such that the application(s) canimmediately access the replicated data rather than having to wait forthe data to be restored onto the source storage device 318. While theclient computing device 302 accesses the destination storage device 324,the replicated data can be restored onto the source storage device 318in parallel.

The method 400 can include fewer, more, or different blocks than thoseillustrated in FIG. 4 and/or one or more blocks illustrated in FIG. 4may be modified, omitted, or switched without departing from the spiritand scope of the description. Moreover, it will be appreciated by thoseskilled in the art and others that some or all of the functionsdescribed in this disclosure may be embodied in software executed by oneor more processors of the disclosed components and/or mobilecommunication devices. The software may be persistently stored in anytype of non-volatile storage.

In some cases, the operating environment may not allow the sourcereplication agent 320 to include all of the information in a journalqueue entry that is needed to write the changed data to the destinationdevice 310 or the recovery point store 336 (e.g., due to the cacheassociated with the journal queue running out of space). For example,the rate at which I/O operations occur on the client computing device302 and the rate at which entries are added to the journal queue may befar greater than the rate at which recovery points are generated basedon the journal queue entries and added to the recovery point store 336.As another example, the network connection between the client computingdevice 302 and the secondary storage computing device 306 may undergotemporary latency issues, and data cannot be transferred to the recoverypoint store 336 fast enough. In such cases, only a portion of theinformation that is normally included in a journal queue entry may beincluded in the entries for a temporary period (e.g., until the cachespace issue is resolved). An improved method for performing block-leveldata replication in dehydration mode is described in greater detail withreference to FIG. 7 .

FIG. 7 is a flow diagram illustrating one embodiment of a method 700 forperforming block-level data replication in dehydration mode. The method700 is described with respect to the system 300 of FIG. 3 . However, oneor more of the steps of the method 700 may be implemented by otherinformation management systems, such as those described in greaterdetail above with reference to FIG. 1D. The method 700 can beimplemented by any one of, or a combination of, of a client computingdevice, a destination device, a storage manager, a data agent, a mediaagent, and the like. Although the steps in the method 700 are describedas being performed by the source replication agent 320 of the system300, the embodiments discussed herein are not limited as such, and oneor more of the steps in the method 700 may be performed by othercomponents of the system 300 (e.g., the destination replication agent322, the storage manager 304, and/or the media agent 332), either aloneor in combination.

At block 702, the source replication agent 320 adds one or more entriesto the journal queue. For example, source replication agent 320 may addthe entries according to the techniques described with reference to FIG.5 .

At block 704, the source replication agent 320 determines that athreshold condition for entering dehydration mode is satisfied. Forexample, the source replication agent 320 may determine that thethreshold condition is satisfied (i) based on the I/O activity on theclient computing device 302 exceeding a threshold level, (ii) based onthe network connection quality, speed, throughput, and/or resourcesbeing below a threshold level, (iii) based on the performance of therecovery point store 336 (e.g., speed, response time, etc.) being belowa threshold level, (iv) based on the rate at which recovery points arewritten to the recovery point store 336 being slower than the rate atwhich entries are added to the journal queue, (v) based on the cacheassociated with the journal queue being full or reaching a thresholdlevel of its capacity, or any combination thereof.

At block 706, the source replication agent 320 adds dehydrated entriesto the journal queue. For example, the source replication agent 320 mayadd, instead of a full entry (or hydrated entry) having both metadataassociated with the I/O operation resulting in a change to the sourcestorage device 318 and the data associated with the I/O operation, adehydrated entry that contains the metadata associated with the I/Ooperation but not the data associated with the I/O operation. As anotherexample, the source replication agent 320 may add, instead of a fullentry or a dehydrated entry, an entry that contains only part of themetadata (e.g., location of the changed block in the source storagedevice 318).

In some embodiments, there are two types of dehydration mode, (i) one inwhich the metadata but not the actual data associated with the I/Ooperation is stored in the journal queue (“first dehydration mode”), and(ii) another in which only part of the metadata associated with the I/Ooperation (e.g., location of the changed block in the source storagedevice 318) is stored without the actual data (“second dehydrationmode”). In such embodiments, at block 704, the source replication agent320 may utilize two threshold levels such that based on one or more ofthe criteria described above (e.g., I/O activity, network connectionquality, speed, throughput, and/or resources, recovery point storeperformance, the rate at which the recovery points are written, and thecache capacity) being below (or above) a first threshold level, thesource replication agent 320 may enter the first dehydration mode, basedon such criteria being between the first threshold level and a secondthreshold level, enter the second dehydration mode, and based on suchcriteria being above (or below) the second threshold level, enter themode in which full entries are added to the journal queue.

At block 708, the source replication agent 320 identifies, based on themetadata associated with or included in the dehydrated entry, thelocation of the actual data corresponding to one or more of thedehydrated entries (e.g., data that was not included in the dehydratedentries based on the threshold condition of block 704 being satisfied).For example, the metadata associated with the dehydrated entries mayindicate the location of the data block in the source volume that ischanged by the write operation(s) corresponding to the dehydratedjournal queue entries.

In some embodiments, the source replication agent 320 identifies thelocation of the data corresponding to the dehydrated entries at block708 based on determining that the threshold condition of block 704 is nolonger satisfied. In other embodiments, the source replication agent 320identifies the location of the data corresponding to the dehydratedentries at block 708 regardless of whether the threshold condition ofblock 704 is satisfied or not (e.g., without first determining that thethreshold condition is no longer satisfied).

At block 710, the source replication agent 320 determines whether datacorresponding to the dehydrated entries have changed (e.g., overwrittenby another change to the same data block) after the change correspondingto the dehydrated entries was made. For example, after a first writeoperation modified a data block in the source storage device, and adehydrated entry was generated and added to the journal queue inresponse to the modification, if the same data block was furthermodified by a second write operation before the source replication agent320 had a chance to store the data corresponding to the change caused bythe first write operation, the sequence of changes to the source storagedevice 318 is broken (e.g., the change caused by the first writeoperation was never recorded so the journal queue entries can no longerbe used to create recovery points since the changes cannot be written insequence). If the same data block has not been modified since the changecaused by the first write operation, the data block can be read from thesource storage device 318 and added to the dehydrated entry, therebyhydrating the dehydrated entry. If the data block was modified, themethod 700 proceeds to block 712. Otherwise, the method 700 proceeds toblock 716.

At block 712, the source replication agent 320, based on determiningthat the data corresponding to the dehydrated entries have changed afterthe change corresponding to the dehydrated entries was made, discardsthe data corresponding to the dehydrated entries (e.g., refrains fromwriting the data to the destination device 310 or the recovery pointstore 336).

At block 714, the source replication agent 320 refrains from creatingrecovery points (e.g., in granular replication mode) until a thresholdcondition for exiting dehydration mode is satisfied. The sourcereplication agent 320 may subsequently determine whether the thresholdcondition for exiting dehydration mode is satisfied, and based on thethreshold condition for exiting dehydration mode being satisfied, thesource replication agent 320 may begin adding hydrated entries to thejournal queue again and also begin adding recovery points to therecovery point store 336 again.

At block 716, the source replication agent 320, based on determiningthat the data corresponding to the dehydrated entries have not changedafter the change corresponding to the dehydrated entries was made,writes the data corresponding to the dehydrated entries to thedestination device 310 (or the recovery point store 336).

At block 718, the source replication agent 320 continues creatingrecovery points. The source replication agent 320 may repeat theoperations at blocks 706, 708, 710, 716, and 718 until the determinationat block 710 is positive. Alternatively or additionally, the sourcereplication agent 320 may begin adding hydrated entries to the journalqueue again and continue adding recovery points to the recovery pointstore 336 until the threshold condition for entering dehydration mode issatisfied again.

The method 700 can include fewer, more, or different blocks than thoseillustrated in FIG. 7 and/or one or more blocks illustrated in FIG. 7may be modified, omitted, or switched without departing from the spiritand scope of the description. Moreover, it will be appreciated by thoseskilled in the art and others that some or all of the functionsdescribed in this disclosure may be embodied in software executed by oneor more processors of the disclosed components and/or mobilecommunication devices. The software may be persistently stored in anytype of non-volatile storage.

In some cases, a recovery point may lose its value as the recovery pointgets old. For example, if the user would not be particularly interestedin reverting the state of a storage volume back to where it was days ormonths ago, the user may not need the recovery point store 336 to holdonto recovery points that are older than a threshold level, especiallyif the recovery point store 336 contains newer, acceptable recoverypoints that the user could utilize instead. Even in cases where sucholder recovery points are desired, recovery points that are over 2 yearsold, for example, may not need to be maintained at the 1-hour intervalat which new recovery points are generated. Also, storage constraintsmay limit the amount of data and/or the number of recovery points thatcan be maintained in the recovery point store 336. In such cases, theuser may wish to either delete recovery points that are older than athreshold level and/or merge some of the recovery points older than athreshold level such that the older recovery points are temporally morespaced apart than the newer recovery points (e.g., recovery pointsgenerated more than 48 hours ago are 12 hours apart, whereas recoverypoints generated less than 48 hours ago are 2 hours apart). An improvedmethod for merging recovery points is described in greater detail withreference to FIG. 8 .

FIG. 8 is a flow diagram illustrating one embodiment of a method 800 formerging recovery points in a recovery point store. The method 800 isdescribed with respect to the system 300 of FIG. 3 . However, one ormore of the steps of the method 800 may be implemented by otherinformation management systems, such as those described in greaterdetail above with reference to FIG. 1D. The method 800 can beimplemented by any one of, or a combination of, of a client computingdevice, a destination device, a storage manager, a data agent, a mediaagent, and the like. Although the steps in the method 800 are describedas being performed by the destination replication agent 322 destinationreplication agent 322 of the system 300, the embodiments discussedherein are not limited as such, and one or more of the steps in themethod 800 may be performed by other components of the system 300 (e.g.,the source replication agent 320, the storage manager 304, and/or themedia agent 332), either alone or in combination.

At block 802, the destination replication agent 322 generates recoverypoints at a first interval. For example, the destination replicationagent 322 may generate the recovery points at every 5 minutes, every 10minutes, every half hour, every hour, every 2 hours, every 24 hours, orthe like. The first interval (e.g., recovery point interval) at whichthe recover points are generated may be specified by a user and/ordetermined based on a default value.

At block 804, the destination replication agent 322 determines that amerge condition for merging two or more recovery points is satisfied. Insome embodiments, the destination replication agent 322 may determinethat the merge condition is satisfied based on the time associated withone of the recovery points reaching a threshold time value. For example,the destination replication agent 322 may determine that the user hasspecified that recovery points older than a specific age (e.g., 48 hoursold) are to be merged with one or more other recovery points (e.g.,immediately preceding or immediately following) such that the mergedrecovery point is associated with (e.g., reflects the state of thesource storage device at) a time that is spaced apart from the closestrecovery point in the recovery point store by a time interval (e.g.,“second interval”) that is different from the time interval (e.g.,“first interval”) at which the recovery points are initially generatedand added to the recovery point store 336. One or both of the firstinterval and the second interval may be specified by the user (oranother component of the system shown in FIG. 3 ) or may be a defaultvalue. In some embodiments, the second interval is longer than the firstinterval.

At block 806, the destination replication agent 322 merges two or moreexisting recovery points into a single recovery point having the secondinterval. For example, the user may specify that any recovery pointsolder than 2 days old should be merged such that the merged recoverypoints are 6 hours apart, and any recovery points older than 14 days oldshould be further merged such that the merged recovery points are 1 dayapart. In such an example, the destination replication agent 322 mayinitially cause recovery points to be generated and added to therecovery point store 336 at every 2 hours, and the recovery pointsstored in the recovery point store 336 may be as shown in Table 1:

TABLE 1 Recovery points stored in the recovery point store 336 RecoveryPoint ID Recovery Point Time Age Z0012 2019-06-25 12:00 0 hrs Z00112019-06-25 10:00 2 hrs Z0010 2019-06-25 08:00 4 hrs . . . . . . . . .Q0098 2019-06-23 14:00 1 day 22 hrs Q0097 2019-06-23 12:00 2 days Q00942019-06-23 06:00 2 days and 6 hrs . . . . . . . . . K0017 2019-06-1118:00 13 days 18 hrs K0020 2019-06-11 12:00 14 days K0008 2019-06-1012:00 15 days . . . . . . . . .

Merging two or more recovery points may involve combining all of thechanges to the source storage device (or to a specific storage volume)reflected in the two or more recovery points into a single recoverypoint, such that, if three 2-hour recovery points are being merged, themerged recovery point would include all of the changes made to thesource storage device (or to a specific storage volume) during the6-hour period spanned by the three 2-hour recovery points. In theexample of Table 1, the merged recovery point K0020 would contain all ofthe changes made between 2019-06-10 12:00 and 2019-06-11 12:00, and themerged recovery point Q0097 would contain all of the changes madebetween 2019-06-23 06:00 and 2019-06-23 12:00. Although the example ofTable 1 shows two levels of merging (e.g., 1 hour to 6 hours, and 6hours to 24 hours), in other embodiments, the system described hereinmay allow the user to specify any number of levels (e.g., 1, 2, 3, 4,etc.) and the corresponding merging intervals (e.g., 1 hour, 2 hours, 4hours, 6 hours, 12 hours, 24 hours, etc.)

At block 808, the destination replication agent 322 writes additionaldata to the destination device 310 based on the merged recovery point.Additional data as used herein may refer to the data reflecting theblock-level changes made to the source storage device during the periodencompassed by merged recovery point. After such additional data hasbeen written, the destination storage device 324 may reflect the stateof the source storage device 318 at the time associated with the mergedrecovery point. For example, if the merged recovery point representedapproximately 48 hours ago at the time the additional data is written tothe destination device 310, after the destination storage device 324 isupdated based on the additional data, the destination storage device 324will reflect the state of the source storage device 318 approximately 48hours ago.

In some embodiments, the merged recovery point is removed from therecovery point store 336 after such additional data has been written tothe destination device 310. In some of such embodiments, the additionaldata may be written to the destination device 310 based on a retentionperiod having elapsed. For example, the destination replication agent322 may determine that the user-specified retention period is 2 days,and once a recovery point becomes 2 days old, the destinationreplication agent 322 may cause the data associated with the recoverypoint to be written to the destination device 310 and delete therecovery point.

As another example, the destination replication agent 322 mayperiodically (e.g., once every retention period) cause the dataassociated with the recovery point that is as old as the retentionperiod (e.g., 2 days old in the example above) to be written to thedestination device 310, thereby causing the destination storage deviceto reflect the state of the source storage device one retention periodago (e.g., 2 days ago). After the data is written to the destinationdevice 310, the destination replication agent 322 may cause the recoverypoint associated with the data (and any other recovery points older thanthe recovery point) to be deleted from the recovery point store 336.

Then, after another retention period has elapsed, the recovery pointstore 336 would have accumulated 2 days' worth of recovery points (e.g.,recovery points that are now 0-2 days old), and the recovery pointspreviously stored in the recovery point store 336 would have aged by 2days (e.g., recovery points that are now 2-4 days old). Again, thedestination replication agent 322 may cause the data associated with therecovery point that is as old as the retention period (e.g., 2 days),and delete the recovery point along with the other recovery points thatare older than the recovery point (e.g., recovery points that are 2-4days old). Again, after the data is written to the destination device310, the destination storage device may reflect the state of the sourcestorage device one retention period ago (e.g., 2 days ago).

By the time the retention period has elapsed for a given recovery point,the recovery point may have been merged with one or more recovery pointsand may encompass a greater time period (e.g., 6 hours) than when therecovery point was initially generated (e.g., 1 hour). For example, sixrecovery points generated at every hour may have been merged togetherinto a recovery point that stores the I/O operations (e.g., data writeoperations) occurring during a 6-hour period.

The method 800 can include fewer, more, or different blocks than thoseillustrated in FIG. 8 and/or one or more blocks illustrated in FIG. 8may be modified, omitted, or switched without departing from the spiritand scope of the description. Moreover, it will be appreciated by thoseskilled in the art and others that some or all of the functionsdescribed in this disclosure may be embodied in software executed by oneor more processors of the disclosed components and/or mobilecommunication devices. The software may be persistently stored in anytype of non-volatile storage.

Other Considerations

In some embodiments, machine learning can be used to update or optimizethe way that the source replication agent 320 and/or destinationreplication agent 322 perform the block-level data replication describedherein. For example, the source replication agent 320 and/or destinationreplication agent 322 can be trained, using unsupervised learning (e.g.,in some cases, further based on additional usage status data or feedbackdata) and/or previously done supervised learning, to update one or moreof its conditions, thresholds, and/or parameters (e.g., for trackingchanges to the source storage device, for transmitting data to thedestination device, for entering and exiting dehydration mode, formerging recovery points, etc.).

In regard to the figures described herein, other embodiments arepossible within the scope of the present disclosure, such that theabove-recited components, steps, blocks, operations, and/ormessages/requests/queries/instructions are differently arranged,sequenced, sub-divided, organized, and/or combined. In some embodiments,a different component described herein or otherwise known in the art mayinitiate or execute a given operation described herein.

Embodiments

Some examples of embodiments of the present disclosure are provided inthis section in the form of methods, systems, and non-transitorycomputer-readable media, without limitation.

According to one embodiment of the present disclosure, a method ofperforming block-level data replication using a recovery point storeincludes: receiving a request to perform a first block-level replicationbetween a source storage device and a destination storage device,wherein the source storage device is configured to store primary datagenerated by one or more applications installed on a client computingdevice, the primary data comprising a plurality of data blocks;receiving an indication that a change was made to a first block storedin the source storage device, wherein the change is associated with awrite operation performed on the client computing device; determiningwhether the first block-level replication is to be performed in a firstreplication mode; based on determining that the first block-levelreplication is to be performed in the first replication mode, recordingthe change to the first block in a first recovery point store, whereinthe first recovery point store is configured to store a plurality ofrecovery points associated with the source storage device; determiningwhether a condition for updating the destination storage device based onone of the plurality of recovery points stored in the first recoverypoint store is satisfied; and based on determining that the conditionfor updating the destination storage device is satisfied, updating thedestination storage device based on the one of the plurality of recoverypoints stored in the first recovery point store.

The method of the preceding paragraph can include any combination orsub-combination of the following features: where the first replicationmode is a granular replication mode in which changed data is firststored in the first recovery point store prior to being stored in thedestination storage device, and the first recovery point store isconfigured to store at least some historical data not stored in thedestination storage device; where the method includes receiving arequest to perform a second block-level replication between anothersource storage device and another destination storage device in a secondreplication mode different from the first replication mode such that thesecond block-level replication does not utilize the first recovery pointstore; where the second replication mode is a live synchronization modein which changed data is stored directly in the destination storagedevice without first being stored in the first recovery point store;where the plurality of recovery points stored in the first recoverypoint store are each associated with a state of the source storagedevice at a different time; where the method includes, prior toreceiving the indication that the change was made to the first block,performing an initial synchronization between the source storage deviceand the destination storage device, wherein the initial synchronizationcomprises comparing source data stored in the source storage device todestination data stored in the destination storage device, and updatingthe destination data such that the destination data is identical to thesource data; where the plurality of recovery points stored in the firstrecovery point store are each associated with a flag indicative ofwhether the recovery point is an application consistent recovery point;where the method includes, subsequent to updating the destinationstorage device, deleting the recovery point that was used to update thedestination storage device from the first recovery point store; wherethe method includes determining that the condition for updating thedestination storage device is satisfied based on a retention periodassociated with the recovery point that was used to update thedestination storage device having elapsed; and where the plurality ofrecovery points stored in the first recovery point store comprise atleast one crash consistent recovery point and at least one applicationconsistent recovery point.

According to another embodiment, a networked information managementsystem may be configured to perform block-level data replication using arecovery point store. The system may include one or more source storagedevices configured to store primary data; one or more destinationstorage devices configured to store copies of the primary data; and astorage computing device comprising physical hardware. The storagecomputing device may be configured to receive a request to perform afirst block-level replication between a source storage device and adestination storage device, wherein the source storage device isconfigured to store primary data generated by one or more applicationsinstalled on a client computing device, the primary data comprising aplurality of data blocks; receive an indication that a change was madeto a first block stored in the source storage device, wherein the changeis associated with a write operation performed on the client computingdevice; determine whether the first block-level replication is to beperformed in a first replication mode; based on determining that thefirst block-level replication is to be performed in the firstreplication mode, cause the change to the first block to be recorded ina first recovery point store, wherein the first recovery point store isconfigured to store a plurality of recovery points associated with thesource storage device; determine whether a condition for updating thedestination storage device based on one of the plurality of recoverypoints stored in the first recovery point store is satisfied; and basedon determining that the condition for updating the destination storagedevice is satisfied, cause the destination storage device to be updatedbased on the one of the plurality of recovery points stored in the firstrecovery point store.

The networked information management system of the preceding paragraphcan include any combination or sub-combination of the followingfeatures: where the first replication mode is a granular replicationmode in which changed data is first stored in the first recovery pointstore prior to being stored in the destination storage device, and thefirst recovery point store is configured to store at least somehistorical data not stored in the destination storage device; where thestorage computing device is further configured to receive a request toperform a second block-level replication between another source storagedevice and another destination storage device in a second replicationmode different from the first replication mode such that the secondblock-level replication does not utilize the first recovery point store;where the second replication mode is a live synchronization mode inwhich changed data is stored directly in the destination storage devicewithout first being stored in the first recovery point store; where thestorage computing device is further configured to, subsequent to causingthe destination storage device to be updated, delete the recovery pointthat was used to update the destination storage device from the firstrecovery point store; and where the storage computing device is furtherconfigured to determine that the condition for updating the destinationstorage device is satisfied based on a retention period associated withthe recovery point that was used to update the destination storagedevice having elapsed.

According to yet another embodiment, a non-transitory computer-readablemedium may store instructions that, when executed by at least onecomputing device comprising one or more processors and computer memory,cause the at least one computing device to perform operations including:receiving a request to perform a first block-level replication between asource storage device and a destination storage device, wherein thesource storage device is configured to store primary data generated byone or more applications installed on a client computing device, theprimary data comprising a plurality of data blocks; receiving anindication that a change was made to a first block stored in the sourcestorage device, wherein the change is associated with a write operationperformed on the client computing device; determining whether the firstblock-level replication is to be performed in a first replication mode;based on determining that the first block-level replication is to beperformed in the first replication mode, causing the change to the firstblock to be recorded in a first recovery point store, wherein the firstrecovery point store is configured to store a plurality of recoverypoints associated with the source storage device; determining whether acondition for updating the destination storage device based on one ofthe plurality of recovery points stored in the first recovery pointstore is satisfied; and based on determining that the condition forupdating the destination storage device is satisfied, causing thedestination storage device to be updated based on the one of theplurality of recovery points stored in the first recovery point store.

The non-transitory computer-readable medium of the preceding paragraphcan include any combination or sub-combination of the followingfeatures: where the operations further include receiving a request toperform a second block-level replication between another source storagedevice and another destination storage device in a second replicationmode different from the first replication mode, wherein the secondreplication mode is a live synchronization mode in which changed data isstored directly in the destination storage device without first beingstored in the first recovery point store; where the operations furtherinclude, subsequent to causing the destination storage device to beupdated, deleting the recovery point that was used to update thedestination storage device from the first recovery point store; andwhere the operations further include determining that the condition forupdating the destination storage device is satisfied based on aretention period associated with the recovery point that was used toupdate the destination storage device having elapsed.

In other embodiments, a system or systems may operate according to oneor more of the methods and/or computer-readable media recited in thepreceding paragraphs. In yet other embodiments, a method or methods mayoperate according to one or more of the systems and/or computer-readablemedia recited in the preceding paragraphs. In yet more embodiments, acomputer-readable medium or media, excluding transitory propagatingsignals, may cause one or more computing devices having one or moreprocessors and non-transitory computer-readable memory to operateaccording to one or more of the systems and/or methods recited in thepreceding paragraphs.

Terminology

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense, i.e., in the sense of “including, but notlimited to.” As used herein, the terms “connected,” “coupled,” or anyvariant thereof means any connection or coupling, either direct orindirect, between two or more elements; the coupling or connectionbetween the elements can be physical, logical, or a combination thereof.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, refer to this application as awhole and not to any particular portions of this application. Where thecontext permits, words using the singular or plural number may alsoinclude the plural or singular number respectively. The word “or” inreference to a list of two or more items, covers all of the followinginterpretations of the word: any one of the items in the list, all ofthe items in the list, and any combination of the items in the list.Likewise the term “and/or” in reference to a list of two or more items,covers all of the following interpretations of the word: any one of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

In some embodiments, certain operations, acts, events, or functions ofany of the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not allare necessary for the practice of the algorithms). In certainembodiments, operations, acts, functions, or events can be performedconcurrently, e.g., through multi-threaded processing, interruptprocessing, or multiple processors or processor cores or on otherparallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described. Software and other modules mayreside and execute on servers, workstations, personal computers,computerized tablets, PDAs, and other computing devices suitable for thepurposes described herein. Software and other modules may be accessiblevia local computer memory, via a network, via a browser, or via othermeans suitable for the purposes described herein. Data structuresdescribed herein may comprise computer files, variables, programmingarrays, programming structures, or any electronic information storageschemes or methods, or any combinations thereof, suitable for thepurposes described herein. User interface elements described herein maycomprise elements from graphical user interfaces, interactive voiceresponse, command line interfaces, and other suitable interfaces.

Further, processing of the various components of the illustrated systemscan be distributed across multiple machines, networks, and othercomputing resources. Two or more components of a system can be combinedinto fewer components. Various components of the illustrated systems canbe implemented in one or more virtual machines, rather than in dedicatedcomputer hardware systems and/or computing devices. Likewise, the datarepositories shown can represent physical and/or logical data storage,including, e.g., storage area networks or other distributed storagesystems. Moreover, in some embodiments the connections between thecomponents shown represent possible paths of data flow, rather thanactual connections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer,specially-equipped computer (e.g., comprising a high-performancedatabase server, a graphics subsystem, etc.) or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor(s) of the computer or other programmabledata processing apparatus, create means for implementing the actsspecified in the flow chart and/or block diagram block or blocks. Thesecomputer program instructions may also be stored in a non-transitorycomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded to a computing device or other programmable data processingapparatus to cause operations to be performed on the computing device orother programmable apparatus to produce a computer implemented processsuch that the instructions which execute on the computing device orother programmable apparatus provide steps for implementing the actsspecified in the flow chart and/or block diagram block or blocks.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference. Aspects of the present disclosure can be modified,if necessary, to employ the systems, functions, and concepts of thevarious references described above to provide yet furtherimplementations of the present disclosure. These and other changes canbe made to the embodiments of the present disclosure in light of theabove Detailed Description. While the above description describescertain examples of embodiments of the present disclosure, and describesthe best mode contemplated, no matter how detailed the above appears intext, the embodiments of the present disclosure can be practiced in manyways. Details of the system may vary considerably in its specificimplementation, while still being encompassed by one or more of theembodiments disclosed herein. As noted above, particular terminologyused when describing certain features or aspects of the presentdisclosure should not be taken to imply that the terminology is beingredefined herein to be restricted to any specific characteristics,features, or aspects of the present disclosure with which thatterminology is associated. In general, the terms used in the followingclaims should not be construed to limit the embodiments of the presentdisclosure to the specific examples disclosed in the specification,unless the above Detailed Description section explicitly defines suchterms. Accordingly, the actual scope of the embodiments encompasses notonly the disclosed examples, but also all equivalent ways of practicingor implementing the embodiments under the claims.

To reduce the number of claims, certain aspects of the presentdisclosure are presented below in certain claim forms, but the applicantcontemplates other aspects of the present disclosure in any number ofclaim forms. Any claims intended to be treated under 35 U.S.C. § 112(f)will begin with the words “means for,” but use of the term “for” in anyother context is not intended to invoke treatment under 35 U.S.C. §112(f). Accordingly, the applicant reserves the right to pursueadditional claims after filing this application, in either thisapplication or in a continuing application.

What is claimed is:
 1. A method of performing block-level datareplication in dehydration mode, the method comprising: determining thata threshold condition for performing replication of data stored on asource storage device onto a destination storage device in dehydrationmode is satisfied; adding a first dehydrated entry to a queue forstoring entries corresponding to data modifications performed on thesource storage device, wherein the first dehydrated entry is associatedwith metadata associated with a first write operation performed on aclient computing device associated with the source storage device;identifying, based at least in part on the metadata associated with thefirst dehydrated entry, a location of data corresponding to the firstdehydrated entry on the source storage device; determining that the datacorresponding to the first dehydrated entry has not changed since theaddition of the first dehydrated entry to the queue; causing the datacorresponding to the first dehydrated entry to be written to thedestination storage device; adding a second dehydrated entry to thequeue, wherein the second dehydrated entry is associated with metadataassociated with a second write operation performed on the clientcomputing device; identifying, based at least in part on the metadataassociated with the second dehydrated entry, a location of datacorresponding to the second dehydrated entry on the source storagedevice; determining that the data corresponding to the second dehydratedentry has changed since the addition of the second dehydrated entry tothe queue; and refraining from causing the data corresponding to thesecond dehydrated entry to be written to the destination storage device.2. The method of claim 1, wherein the first or second dehydrated entryadded to the queue does not include a copy of at least some of the datacorresponding to the first or second dehydrated entry, respectively. 3.The method of claim 1, wherein the metadata associated with the first orsecond dehydrated entry is only a portion of all metadata associatedwith the first or second dehydrated entry, respectively.
 4. The methodof claim 1, wherein the determination that the threshold condition forperforming data replication in dehydration mode is satisfied is madebased on a level of input/output (I/O) activity on the client computingdevice exceeding a threshold level.
 5. The method of claim 1, whereinthe determination that the threshold condition for performing datareplication in dehydration mode is satisfied is made based on aperformance indicator associated with a network between the sourcestorage device and the destination storage device being below athreshold level.
 6. The method of claim 1, wherein the determinationthat the threshold condition for performing data replication indehydration mode is satisfied is made based on a performance valueassociated with a recovery point store associated with the sourcestorage device being below a threshold level.
 7. The method of claim 1,wherein the determination that the threshold condition for performingdata replication in dehydration mode is satisfied is made based on arate at which recovery points are written to a recovery point storeassociated with the source storage device being slower than a rate atwhich entries are added to the queue.
 8. The method of claim 1, whereinthe determination that the threshold condition for performing datareplication in dehydration mode is satisfied is made based on a cacheassociated with the queue being full or having reached a thresholdcapacity level.
 9. A networked information management system configuredto perform block-level data replication in dehydration mode, thenetworked information management system comprising: a source storagedevice configured to store primary data; a destination storage deviceconfigured to store copies of the primary data; and a storage computingdevice comprising physical hardware and configured to: determine that athreshold condition for performing replication of data stored on thesource storage device onto the destination storage device in dehydrationmode is satisfied; add a first dehydrated entry to a queue for storingentries corresponding to data modifications performed on the sourcestorage device, wherein the first dehydrated entry is associated withmetadata associated with a first write operation performed on a clientcomputing device associated with the source storage device; identify,based at least in part on the metadata associated with the firstdehydrated entry, a location of data corresponding to the firstdehydrated entry on the source storage device; determine that the datacorresponding to the first dehydrated entry has not changed since theaddition of the first dehydrated entry to the queue; cause the datacorresponding to the first dehydrated entry to be written to thedestination storage device; add a second dehydrated entry to the queue,wherein the second dehydrated entry is associated with metadataassociated with a second write operation performed on the clientcomputing device; identify, based at least in part on the metadataassociated with the second dehydrated entry, a location of datacorresponding to the second dehydrated entry on the source storagedevice; determine that the data corresponding to the second dehydratedentry has changed since the addition of the second dehydrated entry tothe queue; and refrain from causing the data corresponding to the seconddehydrated entry to be written to the destination storage device. 10.The networked information management system of claim 9, wherein thefirst or second dehydrated entry added to the queue does not include acopy of at least some of the data corresponding to the first or seconddehydrated entry respectively.
 11. The networked information managementsystem of claim 9, wherein the metadata associated with the first orsecond dehydrated entry is only a portion of all metadata associatedwith the first or second dehydrated entry, respectively.
 12. Thenetworked information management system of claim 9, wherein thedetermination that the threshold condition for performing datareplication in dehydration mode is satisfied is made based on a level ofinput/output (I/O) activity on the client computing device exceeding athreshold level.
 13. The networked information management system ofclaim 9, wherein the determination that the threshold condition forperforming data replication in dehydration mode is satisfied is madebased on a performance indicator associated with a network between thesource storage device and the destination storage device being below athreshold level.
 14. The networked information management system ofclaim 9, wherein the determination that the threshold condition forperforming data replication in dehydration mode is satisfied is madebased on a cache associated with the queue being full or having reacheda threshold capacity level.
 15. A non-transitory computer-readablemedium storing instructions, that, when executed by at least onecomputing device comprising one or more processors and computer memory,cause the at least one computing device to perform operationscomprising: determining that a threshold condition for performingreplication of data stored on a source storage device onto a destinationstorage device in dehydration mode is satisfied; adding a firstdehydrated entry to a queue for storing entries corresponding to datamodifications performed on the source storage device, wherein the firstdehydrated entry is associated with metadata associated with a firstwrite operation performed on a client computing device associated withthe source storage device; identifying, based at least in part on themetadata associated with the first dehydrated entry, a location of datacorresponding to the first dehydrated entry on the source storagedevice; determining that the data corresponding to the first dehydratedentry has not changed since the addition of the first dehydrated entryto the queue; causing the data corresponding to the first dehydratedentry to be written to the destination storage device; adding a seconddehydrated entry to the queue, wherein the second dehydrated entry isassociated with metadata associated with a second write operationperformed on the client computing device; identifying, based at least inpart on the metadata associated with the second dehydrated entry, alocation of data corresponding to the second dehydrated entry on thesource storage device; determining that the data corresponding to thesecond dehydrated entry has changed since the addition of the seconddehydrated entry to the queue; and refraining from causing the datacorresponding to the second dehydrated entry to be written to thedestination storage device.
 16. The non-transitory computer-readablemedium of claim 15, wherein the first or second dehydrated entry addedto the queue does not include a copy of at least some of the datacorresponding to the first or second dehydrated entry respectively. 17.The non-transitory computer-readable medium of claim 15, wherein themetadata associated with the first or second dehydrated entry is only aportion of all metadata associated with the first or second dehydratedentry, respectively.